The idea of giving poor people cash, no strings attached, is "very unappealing" for most donors, admits economist Michael Faye -- but it's still one of the best ways to help the poor. Michael and Julia discuss the philosophy behind his organization (GiveDirectly), the evidence we have so far about cash transfers as an anti-poverty intervention, and the various concerns people have about it: How long-lasting are the effects? Does it make recipients less likely to work? Does it cause inflation?

Humanity could thrive for millions of years -- unless our future is cut short by an existential catastrophe. Oxford philosopher Toby Ord explains the possible existential risks we face, including climate change, pandemics, and artificial intelligence. Toby and Julia discuss what led him to take existential risk more seriously, which risks he considers underrated vs. overrated, and how to estimate the probability of existential risk.

Kevin Esvelt, a scientist at MIT, argues that research intended to prevent pandemics is actually putting us in a lot more danger. Also discussed: Kevin's own research on engineering wild animal species. Are the risks worth the benefits?

Ezra Klein explains how Republican and Democrats in the US became so different from each other, ideologically and demographically, and why that trend + our institutions =  political gridlock. Questions covered include: Is polarization necessarily bad? Has the left polarized more than the right? And what should we make of polls that seem to show Republicans and Democrats used to agree on immigration policy?

Kathryn Paige Harden, author of “The Genetic Lottery: Why DNA Matters for Social Equality” explains what scientists have learned about how our genes affect our educational success. Why is this research so controversial? And is it worth doing anyway?

Journalist Kelsey Piper (Future Perfect / Vox) discusses lessons learned from covering COVID: What has she been wrong about, and why? How much can we trust the CDC's advice? What does the evidence look like for different drugs like Fluvoxamine and Ivermectin? And should regular people really try to evaluate the evidence themselves instead of deferring to experts?

Every time there’s an emergency, the prices of certain goods skyrocket -- like masks and hand sanitizer during COVID --  and the public gets angry about price gouging. In this episode, two economists (Raymond Niles and Amihai Glazer) make the case for why “price gouging” is actually a good thing, and Julia raises potential counterarguments.

When you see a statistic reported in the news, like "10% of University of California Berkeley students were homeless this year," how do you evaluate it? You shouldn't blindly accept every statistic you read. But neither should you reject everything that sounds surprising. Tim Harford, economist and author of The Data Detective: Ten Easy Rules to Make Sense of Statistics, talks about the heuristics he recommends using, and the mistakes people tend to make.

How much do Uber and Lyft drivers really earn, after expenses? Are they getting a raw deal by being classified as 'independent contractors' instead of employees? I explore the debate over these questions with three guests: Louis Hyman (Cornell), Veena Dubal (UC Hastings College of the Law), and Harry Campbell (The Rideshare Guy).

Is there any justification for seemingly unjust laws like "qualified immunity," which allows cops to get away with bad behavior? William Baude, a leading scholar of constitutional law, explores how these laws came to be and why they're so hard to change. Also, Baude makes the case for originalism, the view that judges should base their rulings on the original meaning of the Constitution. And Baude explains how rationalist principles have influenced his teaching and legal scholarship.

Julia and guest Vitalik Buterin (creator of the open-source blockchain platform Ethereum) explore a wide range of topics, including: Vitalik's intellectually honest approach to leadership, why prediction markets appear to be biased in favor of Trump, whether it was rational to invest in Bitcoin ten years ago, Vitalik's defense of life extension research against its critics, and more.

Julia and social psychologist Jonathan Haidt (The Righteous Mind) discuss his moral foundations theory and argue about whether liberals should “expand their moral horizons” by learning to think like conservatives. Julia solicits Jon’s help in understanding her disagreement with philosopher Michael Sandel, in episode 247, over the morality of consensual cannibalism.

Matt Yglesias talks about One Billion Americans, his book arguing that it’s in the United States’ national interest to dramatically boost its population, by expanding immigration and having more babies. Matt and Julia also discuss arguments for and against the “YIMBY” movement, which pushes for building more housing; what they’ve both learned from reflecting on their misguided support for the Iraq War in 2003; and why (and how) Matt is trying to be more of a rationalist.

Companies like Twitter and Facebook are increasingly willing to ban users -- and even if you agree with their decisions, is it worrying that a few companies have so much power? Julia discusses with Julian Sanchez, expert on tech and civil liberties.

Coleman Hughes explains why he favors a "colorblind" ideal and why the "race-conscious" camp disagrees with him. Coleman and Julia also discuss whether reparations are just, and what counts as racism.

Data scientist David Shor discusses some of the bad choices made by Democratic political campaigns. What's the cause of the errors? Is it irrationality, coordination problems, or something else?

Harvard philosopher Michael Sandel argues with Julia about human dignity, consensual cannibalism, and the case in his new book, The Tyranny of Merit, that meritocracy is to blame for recent populist backlashes in the U.S.

Economist and Nobel Laureate Angus Deaton discusses the rise in “deaths of despair” in the U.S. – deaths from drugs, alcohol or suicide. What's causing it, and how do we know? Also, Julia and Angus debate whether effective altruism can help the poor.

Rationally Speaking returns from hiatus with a look at a clash between two generations: Millennials, and their parents' generation, the Baby Boomers. Faced with stagnant wages and rising costs of education, rent, and health care, Millennials have a tougher path to economic security than Boomers did. And a growing number of millennial writers argue that their situation is the result of misguided and irresponsible policy choices made by the Boomers themselves.  Are they right? Are Boomers to blame for Millennials' current economic struggles? To answer this question, Julia gets three different perspectives: Jill Filipovic, author of OK Boomer, Let's Talk: How My Generation Got Left Behind, Joseph C. Sternberg, author of The Theft of a Decade: How the Baby Boomers Stole Millennials' Economic Future, and Patrick Fisher, author of Demographic Gaps in American Political Behavior.

This episode features a pair of interviews on a similar topic: First, Stephanie Lepp (host of the Reckonings podcast) discusses what she's learned from interviewing people who had a serious change of heart, or "reckoning," including a former Neo-nazi and a former sex offender. What causes a reckoning? Second, Buster Benson (author of Why Are We Yelling? The art of productive disagreement) shares his tips for coming away from a disagreement feeling more alive -- for example, don't just focus on the literal arguments the other person is making; drill deeper. Buster and Julia debate whether there's a downside to approaching disagreements emotionally, rather than intellectually.

The idea of open borders -- letting people move freely between countries, taking a job wherever they can find a job they want -- is still a pretty fringe position, politically speaking. But economist Bryan Caplan makes a compelling case for it in his new graphic nonfiction book, "Open Borders: The Science and Ethics of Immigration," illustrated by cartoonist Zach Weinersmith. In this episode, Julia questions Bryan about several aspects of his case.

Philosopher of mind Keith Frankish is one of the leading proponents of "illusionism," the theory that argues that your subjective experience -- i.e., the "what it is like" to be you -- is a trick of the mind. It's a counterintuitive theory, but Keith makes the case for it in this episode, while explaining the other leading theories of consciousness and why he rejects them.

The Stanford Prison Experiment is one of the most famous psychology experiments in history. For decades, we've been told that it proves how regular people easily turn sadistic when they are asked to role play as prison guards. But the story now appears to be mostly fraudulent. Thibault Le Texier is a researcher who dug into the Stanford archives and learned that the "prison guards" were actually told how to behave in order to support the experimenters' thesis. On this episode, Thibault and Julia discuss his findings, how the experimenters got away with such a significant misrepresentation for so long, and what this whole affair says about the field of psychology.

If you want to understand why things go wrong in business, government, education, psychology, AI, and more, you need to know Goodhart's Law: "When a measure becomes a target, it ceases to become a good measure." In this episode, decision theorist David Manheim explains the dynamics behind Goodhart's Law and some potential solutions to it.

Several recent books have argued there's no difference between male and female brains. Saloni Dattani, a PhD in psychiatric genetics, discusses some of the problems with the argument, and what we really know so far about gender and the brain.

It's rare for public intellectuals to talk about things they've gotten wrong, but geneticist Razib Khan is an exception. He recently published list of 28 things he's changed his mind about in the last decade, not just in genetics, but in other fields of science, politics, society, and religion. Julia interviews Razib about some of the items on the list -- why did he change his mind, and what lessons does he feel he's learned from his past errors?

It's common wisdom that spending a lot of time on your smartphone, or checking social media like Facebook and Twitter, takes a psychological toll. It makes us depressed, insecure, anxious, and isolated -- or so people say. But is there any research to back that up? Julia discusses the evidence with professor Andy Przybylski, director of research at the Oxford Internet Institute.

Over the last two decades, the prices of consumer goods like toys and electronics have gone way down, but the prices of health care and education have gone up roughly 200%. Why? In this episode, economist Alex Tabarrok discusses his latest book, co-authored with Eric Heller, "Why are the Prices So D*mn High?," which blames rising costs on a phenomenon called the Baumol Effect.

We typically think of violence as being caused by a lack of control, or by selfish motives. But what if, more often than not, violence is intended to be morally righteous? That's the thesis of the book Virtuous Violence: Hurting and Killing to Create, Sustain, End, and Honor Social Relationships. Author Tage Rai debates his book's thesis with Julia. Plus: What does The Iliad teach us about changing attitudes about morality over time?

The global poverty rate has fallen significantly over the last few decades. But there's a heated debate, between people like psychologist Steven Pinker and anthropologist Jason Hickel, over how to view that fact. Is it a triumph for capitalism? Should we celebrate it, or lament the fact that rich countries aren't doing more to close the poverty gap faster? Vox journalist Dylan Matthews explains the disagreement. He and Julia discuss the strengths and weaknesses of each side's argument.

Technology writer Clive Thompson discusses his latest book, Coders: The Making of a New Tribe and the Remaking of the World. Topics Clive and Julia cover include: - Why coders love efficiency so much - Are there downsides to efficiency? - Do coders have particular blindspots when it comes to human nature? - What is a "10x Coder," and why do people disagree about whether they exist? - Does Clive still agree with his older book, "Smarter Than You Think," which argued that technology is making us smarter?

Economist Tyler Cowen discusses his latest book, "Big Business: A love-letter to an American anti-hero." Why has anti-capitalist sentiment increased recently, and to what extent is it justified? How much are corporations to blame for wage stagnation, climbing cost of living, or the slow response to climate change? Tyler and Julia also explore their various disagreements: on how to communicate, whether people should bet on their beliefs, and whether we should increase public optimism about technology.

Helen Toner, the director of strategy at Georgetown's Center for Security and Emerging Technology (CSET), shares her observations from the last few years of talking with AI scientists and policymakers in the US and China. Helen and Julia discuss, among other things: How do the views of Chinese and American AI scientists differ? How is media coverage of China misleading? Why the notion of an "AI arms race" is flawed Why measures of China's AI capabilities are overstated Reasons for optimism and pessimism about international cooperation over AI

This episode features journalist Kelsey Piper, blogger and journalist for "Future Perfect," a new site focused on topics that impact the long-term future of the world. Kelsey and Julia discuss some of her recent stories, including why people disagree about AI risk, and how she came up with her probabilistic predictions for 2018. They also discuss topics from Kelsey's personal blog, including why it's not necessarily a good idea to read articles you strongly disagree with, why "sovereignty" is such an important virtue, and the pros and cons of the steel man technique.

This episode features John Nerst, data scientist and blogger at everythingstudies.com, discussing a potential new field called "erisology," the study of disagreement. John and Julia discuss why Twitter makes disagreement so hard; whether there's anything to learn from postmodernism; John's "signal and corrective" model that explains why disagreement persists even when people agree on the key facts; and how the concept of "decoupling" helps explains Sam Harris and Ezra Klein's debate last year about IQ.

In the wake of the University of California's decision to end their contract with Elsevier, the world's largest scientific publisher, a lot of people have been talking about the effect that publishers like Elsevier have on the progress of science. William Gunn, director of scholarly communications for Elsevier, and Alex Holcombe, cognitive scientist and open science advocate, discuss their differing perspectives on the question. The discussion includes: What are scientists' main complaints about Elsevier? What value does Elsevier add? Is the academic publishing market a functioning one? Can Elsevier be a force for innovation?

This episode features Sarah Haider, the president of Ex-Muslims of North America. Julia and Sarah discuss why it's important to talk about the challenges of leaving Islam, and why that makes people uncomfortable or angry. They also explore whether being intellectually honest helps or hurts your effectiveness as an activist; Sarah's concerns with the Intellectual Dark Web; and whether Sarah would draw any lines when it comes to giving offensive views a platform.

If you want to do as much good as possible with your career, what problems should you work on, and what jobs should you consider? This episode features Rob Wiblin, director of research for effective altruist organization 80,000 Hours, and the host of the 80,000 Hours podcast. Julia and Rob discuss how the career advice 80,000 Hours gives has changed over the years, and the biggest misconceptions about their views. Their conversation covers topics like: - Should everyone try to get a job in finance and donate their income? - The case for working to reduce global catastrophic risks - Why reducing risk is a better way to help the future than increasing economic growth - What percentage of the world should ideally follow 80,000 Hours advice?

This episode features Neerav Kingsland, who helped rebuild New Orleans' public school system after Hurricane Katrina, converting it into the country's first nearly-100% charter school system. Neerav and Julia discuss: why Neerav believes the evidence shows charter schools work better than regular public schools, his responses to the main arguments against charters, and what we know about how parents choose schools for their children.

This episode features Rick Nevin, an economist who is known for his research suggesting that lead is one of the main causes of crime. Rick and Julia discuss: how do we know the correlation between lead and crime is a sign of a causal relationship? Has the lead-crime theory made any successful predictions? And is it possible that getting rid of lead could reduce the crime rate down to zero?

Not enough people know about the Mohists, a strikingly modern group of Chinese philosophers active in 479-221 BCE. This episode features Chris Fraser, expert on Mohism and professor of philosophy at the University of Hong Kong. Chris and Julia discuss how the Mohists put their philosophy into practice and got Chinese leaders to hold off on starting wars; how their philosophy was similar to and different from modern consequentialism; why their movement died out, and what modern groups like Effective Altruists can learn from their story.

This episode features the hosts of "Ask a Mathematician, Ask a Physicist," a blog that grew out of a Burning Man booth in which a good-natured mathematician (Spencer Greenberg) and physicist (Seth Cottrell) answer people's questions about life, the universe, and everything. Spencer and Seth discuss the weirdest and most controversial questions they've answered, why math is fundamentally arbitrary, Seth's preferred alternative to the Many Worlds Interpretation of quantum physics, how a weird group of parapsychologists changed the field of physics, and whether you could do a Double Slit Experiment with a Cat Cannon.

This episode features political scientist Rob Reich, author of "Just Giving: Why Philanthropy is Failing Democracy, and How it Can Do Better". Rob and Julia debate his criticisms of philanthropy: Does it deserve to be tax-deductible? Is it a violation of the autonomy of recipients to attach strings to their charitable gifts? And do philanthropists have too much power in society?

This episode features Peter Eckersley, an expert in law and computer science, who has worked with the Electronic Frontier Foundation and the Partnership on AI. Peter and Julia first delve into some of the most fundamental questions about privacy: What are the risks of losing privacy? Do we have more to fear from governments or industry? Which companies do a good job of protecting their users' privacy? Are there tradeoffs between supporting privacy and supporting competitive markets? Next, they discuss Peter's work measuring recent progress in AI, and debate to what extent recent progress is cause for optimism.

In this episode, economist Jason Collins discusses some of the problems with behavioral economics: Why governments have started to rely too much on the field, and why that's bad; why it's suspicious that there are over 100 cognitive biases; when "nudges" are problematic; and more.

In this episode, economist Chris Auld describes some common criticisms of his field and why they're wrong. Julia and Chris also discuss whether there are any good critiques of the field, and whether economists think that people with an addiction to alcohol or drugs are behaving rationally.

Aviv Ovadya, an expert on misinformation, talks with Julia about the multiple phenomena that get lumped together as "fake news." For example, articles that are straightforwardly false, misleading, or artificially created (think "Deepfakes," videos that make a politician appear to say something he didn't say). Which of those problems are more dangerous for our civilization? Are any of them tractable? And what might a solution look like?

On this episode of Rationally Speaking, professor Diana Fleischman makes the case for transhumanist evolutionary psychology: understanding our evolved drives, so that we can better overcome them. Diana and Julia discuss sexual preferences, jealousy, and other drives -- how immutable are they? How do we know? And how would it change society, if we could change the distribution of people we find attractive, or normalize new relationship structures such as polyamory?

This episode features Anders Sandberg, a researcher at Oxford's Future of Humanity Institute, explaining several reasons why it's valuable to think about humanity's long-term future. Julia and Anders discuss the common objection that we can't predict or steer the future, and explore whether people really care if humanity dies out.

This episode features physicist Anthony Aguirre discussing Metaculus, the site he created to crowd-source accurate predictions about science and technology. For example, will SpaceX land on Mars by 2030? Anthony and Julia discuss details such as: why it's useful to have predictions on questions like these, how to measure Metaculus' accuracy, why Anthony chose not to run it like a traditional prediction market, and how to design incentives to reward good forecasters.

This episode features Professor Dean Simonton, who has spent his life quantitatively studying geniuses, from Einstein to Mozart. Dean and Julia discuss his views on whether IQ is important, whether some innovations are "in the air" at given points in history, whether the "10,000 hours = mastery" theory promoted by Malcolm Gladwell is accurate, and more.

This episode features neuroscientist Ed Boyden discussing two inventions of his that have revolutionized neuroscience: optogenetics and expansion microscopy. Ed and Julia talk about Ed's approach to coming up with good ideas, why he prefers reading old science to new science, his big-picture plan for what he wants to solve in his career, and his take on the rationalist versus Hayekian debate over how to make important progress.

This episode features physicist Sabine Hossenfelder, author of Lost in Math, arguing that fundamental physics is too enamored of "beauty" as a criterion for evaluating theories of how the universe works. She and Julia discuss the three components of beauty (simplicity, naturalness, and elegance), why physicists think it's reasonable to put their trust in beauty, and why this might be merely a symptom of other underlying problems with physics as a discipline.

This episode features Stuart Ritchie, intelligence researcher and author of the book "Intelligence: All That Matters." Stuart responds to some of the most common conceptual objections to the science of IQ testing. Can we even define intelligence? Aren't there lots of different kinds of intelligence? How do we know the tests are measuring intelligence at all instead of something like motivation or familiarity with the style of testing? Does it undermine the meaningfulness of IQ as a metric that people can improve over time, with practice, or over generations?

This episode features cognitive psychologist Christopher Chabris discussing his research on "collective intelligence" -- why do some teams perform better than others at a wide variety of tasks? Julia discusses potential objections to the findings and how gender-related publication bias should affect our interpretation of them. In the second half of the episode, Julia and Chris discuss why people get so upset at companies like Facebook and OKCupid for doing experiments on their users, and whether that's fair.

This episode features Annie Duke, former pro poker player and author of the book Thinking in Bets: Making Smarter Decisions When You Don't Have All the Facts. Julia and Annie debate why people tend to ignore the role of luck in their decisions, whether expressing uncertainty makes you seem weak, and how people end up engaging in "defensive decision-making," where they're not trying to make the best call so much as simply avoid being blamed for bad outcomes.

Developmental psychologist Alison Gopnik explains why modern parenting is too goal-oriented. Alison and Julia discuss whether anything parents do matters, whether kids should go to school, and how kids learn discipline if you don't force them to do things. They also discuss Alison's reservations about Steven Pinker's book Enlightenment Now, and her concerns about potential downsides of modernity.

When people argue on the internet, you never expect anyone to actually say "You know what, that's a good point, you've changed my view somewhat." But Change My View, a fast-growing subreddit founded by Kal Turnbull, is an exception to the rule. Julia and Kal discuss the culture of Change My View, what makes it such an oasis for reasonable discussion on the Internet, and what we've learned about what motivates people to change their minds or not.

This episode features economist Michael Webb, who recently co-authored a paper titled "Are ideas getting harder to find?" It demonstrates that the number of researchers it takes to produce a technological innovation has gone up dramatically over time. Michael and Julia discuss various possible explanations for why this is happening, along with several challenges to his paper.

Simine Vazire is a professor of psychology, the author of the blog, "Sometimes I'm Wrong," and a major advocate for improving the field of psychology. She and Julia discuss several potential objections to Simine's goal, how to handle criticism, and Simine's psychology research on the question: How self-aware are people about the way they behave?

In 1950, the great physicist Enrico Fermi posed a question that people have been puzzling over ever since: Where is everybody? The universe has been around for billions of years, so why haven't we seen any signs of alien civilizations? This episode features physicist Stephen Webb, who describes some of the potential solutions to the puzzle. Stephen and Julia also discuss questions such as: What evidence have we gotten so far that helps us answer the Fermi problem? How do we estimate how rare/difficult it is for human-level intelligence to evolve? And why does it matter what the answer to Fermi's question is?

In this episode, economist Bryan Caplan argues that the main reason getting a college degree is valuable is because of signaling (i.e., it proves that you have traits that employers value, like conscientiousness and conformity), and not because college teaches you useful knowledge or skills. Julia proposes several potential challenges to Bryan's argument, and they discuss why it matters how much of education's value is signaling.

The security dilemma is a classic problem in geopolitics: Often when one nation takes measures to protect itself from attack (like adding to their stockpile of missiles), other nations see that and worry it means the first nation is preparing to attack them, which leads to a dangerous feedback loop of escalation. In this episode, Ben Buchanan (postdoctoral fellow at Harvard studying cybersecurity and statecraft) explores how this dilemma plays out in the realm of cybersecurity: Why is the dilemma harder to resolve than it used to be with traditional warfare? And is there anything that might help?

This episode features tech and policy journalist Timothy Lee, discussing a question that's increasingly in the spotlight: How much should tech companies be actively moderating their users' speech? For example, should Facebook be trying to fight fake news? Should Twitter ban bullying? Should Reddit ban subreddits that they consider hate speech? Timothy and Julia look at the question not just from the legal perspective, but also from the moral and strategic perspectives as well.

This episode features Jessica Flanigan, professor of normative and applied ethics, making the case that patients should have the right to take pharmaceutical drugs without needing to get a prescription from a doctor. Jessica and Julia discuss a series of related questions, such as: Should there be exceptions made for drugs that have negative repercussions on society as a whole? And what is the morally relevant difference between a doctor imposing treatment on someone without consent, and the government withholding treatment from someone without consent?

In this episode, economist Timur Kuran explains the ubiquitous phenomenon of "preference falsification" -- in which people claim to support something publicly even though they don't support it privately -- and describes its harmful effects on society. He and Julia explore questions like: Is preference falsification all bad? Are there ways to reduce it? And how much has the Internet changed the dynamics around preference falsification?

In this episode Julia talks with Doug Hubbard, author of How to Measure Anything, about why people so often believe things are impossible to quantify like "innovation" or "quality of life." For example, because people often have a deep misunderstanding of the meaning of probability. Or because they're reluctant to violate "sacred taboos" by putting a number on something like the value of human life. Or because it feels vulgar to "reduce" important things to a number. Doug explains how he responds to these objections and others.

Philosopher Eric Schwitzgebel returns to the show to explore several related questions: His taxonomy of the three different styles of thinker -- "Truth," "Dare," and "Wonder" -- and whether one of them is better than the others. His case for why it's bad to interpret people "charitably." And his seemingly paradoxical claim that we are frequently wrong about our own conscious experience.

This episode features Zach Weinersmith, creator of the philosophical webcomic Saturday Morning Breakfast Cereal, and the co-author (with his wife Kelly Weinersmith) of the new book Soonish: 10 Emerging Technologies That'll Improve and/or Ruin Everything. Julia and Zach talk about which new technology is the most likely to happen, which would be most transformative, and which would pose the most risk to the world. Also, has our society become too risk-averse? And what are the main bottlenecks to technological development?

This episode features bestselling author Robert Wright making the case for why Buddhism was right about human nature: its diagnosis that our suffering is mainly due to a failure to see reality clearly, and its prescription that meditation can help us see more clearly. Robert and Julia discuss whether it's suspicious that a religion turned out to be "right" about human nature, what it means for emotions to be true or false, and whether there are downsides to enlightenment.

The field of neuroscience has been collecting more and more data, and developing increasingly advanced technological tools in its race to understand how the brain works. But can those data and tools ever yield true understanding? This episode features neuroscientist and computer scientist Eric Jonas, discussing his provocative paper titled "Could a Neuroscientist Understand a Microprocessor?" in which he applied state-of-the-art neuroscience tools, like lesion analysis, to a computer chip. By applying neuroscience's tools to a system that humans fully understand (because we built it from scratch), he was able to reveal how surprisingly uninformative those tools actually are. Julia and Eric also discuss the related question: what kind of tools *would* we need to really understand the brain?

You may have heard of the Implicit Associations Test (IAT) -- one of the most famous instruments from social psychology, it's frequently cited as evidence that most people harbor implicit racism or sexism, even if they aren't aware of it. This episode features science journalist Jesse Singal, who argues that the IAT has been massively overhyped, and that in fact there's little evidence that it's measuring real-life bias. Jesse and Julia discuss how to interpret the IAT, why it became so popular, and why it's still likely that implicit bias is real, even if the IAT isn't capturing it.

There are a lot of sensitive topics about human nature that would be interesting to study, such as people's sexual behavior, or how racist people really are. Researchers studying those questions have always faced the problem that we tend to lie on surveys -- but we don't lie to Google. This episode features Seth Stephens-Davidowitz, economist and data scientist, and author of the book Everybody Lies: Big Data, New Data, and What the Internet Can Tell Us About Who We Really Are. Seth and Julia discuss the insights new research gives us into which parts of the USA are more racist, what kinds of strategies reduce racism, whether the internet is making political polarization worse, and the sexual fetishes and insecurities people will only admit to their search engine.

You've probably heard of Pascal's Wager: That it's rational to believe in God, because if you're wrong it's no big deal, but if you're right then the payoff is huge. This episode features philosopher Amanda Askell, who (though not religious herself) argues that it's much trickier to rebut Pascal's Wager than most people think. Amanda and Julia also discuss how to handle other decisions where a risk has very low probability but would matter a lot if it came true -- should you round them down to zero? Does it matter how measurable the risk is? And should you take into account the chance you're being scammed?

In this episode Julia sits down with neuroscientist and obesity researcher Stephan Guyenet, to talk about what scientists know so far about the causes of obesity, and in particular the brain's role in regulating weight gain. Julia and Stephan cover questions such as: Why did obesity start to increase in the United States in the latter half of the 20th century? Does the body have a "set point" of fat that it tries to defend, and what affects those set points? Are low-carb diets more effective for weight loss than low-fat diets, and if so, what explains the difference?

In this episode, recorded live at the Northeast Conference on Science and Skepticism, Julia interviews evolutionary psychologist Rob Kurzban, author of "Why Everyone (Else) is a Hypocrite." Rob describes the "modular mind" hypothesis, and how it explains hypocrisy, self-deception, and other seemingly irrational features of human nature. Rob and Julia argue about how useful these kinds of "strategic wrongness" really are.

What determines which policies a person votes for? Is it their personality, their upbringing, blind loyalty to their political party? Or is it self-interest -- people voting for policies that will benefit themselves and the groups they belong to? This episode features psychologist Jason Weeden, arguing that self-interest is a much bigger determinant of voter behavior than most political scientists think it is. Jason and Julia talk about why researchers disagree over this question, and what "self-interest" even means.

Humans have an innate urge to reach for explanations of the world around us. For example, "What caused this tragedy?" or "Why are some people successful?" This episode features psychologist and philosopher Tania Lombrozo, discussing her research on what purpose explanation serves -- i.e., why it helps us more than our brains just running prediction algorithms. Tania and Julia also discuss whether simple explanations are more likely to be true, and why we're drawn to teleological explanations (e.g., "Why does the sun shine? So that plants can grow.")

We're used to conflating political parties (Republican and Democrat) with political ideologies (conservative and liberal), but the two were very distinct only a few decades ago. In this episode of Rationally Speaking, Julia talks with political scientist Hans Noel about why the Democrats became the party of liberalism and the Republicans the party of conservatism, whether voters are hypocrites in the way they apply their ostensible ideology, and whether politicians are motivated by ideals or just self-interest.

Nothing changed the course of human history as much as the industrial revolution. Yet its cause is a mystery: Why did it occur in the late 1700s, and not sooner (or later)? Why did it occur in Britain, a relatively small and geographically isolated country, and not somewhere much bigger like China, or elsewhere in Northern Europe like the Netherlands? This episode features economic historian Gregory Clark, author of A Farewell to Alms and one of the leading scholars of the industrial revolution. Greg and Julia explore different theories, as well as the epistemological challenges of answering this kind of causal question about history.

What if you had the opportunity to become a vampire, irreversibly -- and everyone you knew who had become one said "It's utterly indescribable." Would you take the leap, not knowing what it would feel like, or how it would change your personality and values? That's an example of what philosopher L. A. Paul calls a "transformative experience," one that's especially hard to choose (or forgo) rationally, because of how unknowable it is and how it changes your very preferences. In this episode, she and Julia discuss real life examples of transformative experiences -- such as having children -- and debate how to deal with them.

This episode features mathematician and social entrepreneur Spencer Greenberg, talking about how he's taking advantage of the Internet to improve the research process. Spencer and Julia explore topics such as: how the meaning of your research can change dramatically when you ask people *why* they gave the answers they did on your survey, how the sheer speed of online research can help us solve the p-hacking problem, and how to incentivize scientists to share their data and methods.

This episode introduces "moral uncertainty," the idea that you shouldn't be overly confident in your moral judgments -- like whether it's okay to eat meat, for example, or whether it's okay to abort a baby. The episode's guest is Will MacAskill, a founder of the effective altruism movement and Oxford professor of philosophy. Julia and Will discuss how to take multiple moral systems into account when making a decision, and how to deal with "absolutist" theories that insist some actions have infinite badness, like lying.

In this episode of Rationally Speaking, Julia talks with economics and public policy expert David Roodman about the "Worm Wars" in social science -- the debate over whether deworming pills are an effective way to fight poverty. Along the way they discuss how to analyze a study, the differences between economists and epidemiologists, and how to make high stakes decisions when all your evidence is flawed.

This episode features Harvard economist Dani Rodrik, talking about the epistemology of economics: Are there any general "laws" of economics that we can be really confident in? Do economists discard models if the data doesn't support them? And why do economists disagree with each other?

This episode features Tim Urban, author of popular longform illustrated blog Wait But Why. Julia and Tim explore one of their common interests: the tension between the rational and irrational aspects of human nature. Is there any value in the "irrational" parts of us (such as Tim's colorfully named "instant gratification monkey" and "social approval mammoth")? And can recognizing that tension help us live better -- or are we stuck struggling between our animal and rational selves?

If you're a healthy adult, should you donate one of your kidneys to a stranger? This episode features journalist Dylan Matthews, who donated his kidney last year. He and Julia discuss the clever design of "donor chains," how we should evaluate the science about whether kidney donation is safe, and whether we have an ethical obligation to donate.

Churchill famously called democracy "the worst system of government, except for all the others that have been tried." Could we do better? On this episode of Rationally Speaking, Julia chats with professor Jason Brennan, author of the book "Against Democracy," about his case for why democracy is flawed -- philosophically, morally, and empirically.

This episode explores the economics and ethics of low-paying factories (which some might call "sweatshops") in Ethiopia. Do they make their workers better off, relative to those people's outside options? Professor Chris Blattman has run some well-designed randomized controlled trials exploring this question, and he discusses what surprised him and how he's updated his views from his research. Julia and Chris also discuss an innovative program to reduce crime in Liberia using cognitive behavioral therapy.

Over the last two decades, the Evidence-Based Medicine (EBM) movement has transformed medical science, pushing doctors to rely less on intuition or "common wisdom" in choosing treatments, and more on evidence from studies. Sounds great -- but has EBM become a victim of its own success? This episode features John Ioannidis, Stanford professor of medicine, health and policy, and statistics, and author of the famous paper, "Why Most Published Research Findings are False." John and Julia discuss how EBM has been "hijacked," by whom, and what do do about it.

Since Trump's surprising win in the 2016 presidential election, there's been a flurry of discussion about why things turned out this way. But which explanations are well-supported, and which are wrong (or simply rationalizations)? This episode features political scientist Brendan Nyhan, who talks with Julia about questions like: Were the polls and models wrong? If so, why? How surprised should we have been by Trump's win? And why didn't the markets react badly to it?

There's a growing anxiety about the quality of scientific research, as a depressingly large fraction of articles fail to replicate. Could "openness" solve that problem? This episode features Brian Nosek, a professor of psychology and founder of the Center for Open Science. He and Julia discuss what openness means, some clever approaches to boosting openness, and whether openness could have any downsides (for example, in the cases of peer review or data sharing).

It can be pretty frustrating to live in a "safe" state during national elections, where the chance your vote will affect the overall results is practically zero. This episode, with professor Scott Aaronson, explores an unorthodox solution to the problem: "swapping" your vote with someone in a swing state who was going to vote for a third party candidate. Scott and Julia explore the game theory of vote swapping, and whether there are any ethical problems with it.

How did "social justice" come to mean what it does today? This episode features a chat with Will Wilkinson, a writer, political philosopher, and vice president of policy for the Niskanen Institute. Will and Julia discuss the libertarian reaction to social justice, whether or not social justice is a zero-sum game, and how the Internet exacerbates conflicts over social justice.

What can we do now to affect whether humanity is still around in 1000 years (and what life will be like then)? In this episode, Julia talks with Owen Cotton-Barratt, a mathematician at Oxford's Future of Humanity Institute. They cover questions like: Given our poor track record of forecasting, is there any point to speculating about the far future? And is it rational to prioritize current people over future people?

This episode features a chat with Don Moore, professor of management of organizations at the University of California Berkeley's Haas School of Business, and an expert in overconfidence. Don and Julia discuss the various forms of overconfidence, whether its upsides are big enough to outweigh its downsides, and what people mean when they insist "I think things are better than they really are."

As the technology we rely on every day becomes increasingly sophisticated, it's getting to the point where it's too complicated to understand -- not just for individual users, but for any human at all. In this episode, Julia talks with complexity scientist Samuel Arbesman, about his new book Overcomplicated: Technology at the Limits of Comprehension, why these unprecedented levels of complexity might be dangerous, and what we should do about it.

Some theories violate common sense so wildly that you want to just reject them out of hand. For example, "The United States is conscious," or "The most moral act would be to replace all living beings with an orgasmic blob." On the other hand, many theories in physics that sounded similarly crazy turned out to be very well-supported (think of quantum theory, or relativity). So what role should "common sense" play in evaluating new theories? This episode features a discussion with philosopher Eric Schwitzgebel on his theory of "Crazyism," that we should expect the truth to be at least a little bit crazy.

If someone asks you, "What caused your success (in finance, your career, etc.)?" what probably comes to mind for you is a story about how you worked hard and made smart choices. Which is likely true -- but what you don't see are all the people who also worked hard and made smart choices, but didn't succeed because luck wasn't on their side. In this episode, Julia chats with professor of economics Robert Frank about his latest book, Success and Luck: The Myth of the Modern Meritocracy. They explore questions like: Why do we discount the role of luck in success? Has luck become more important in recent years? And would acknowledging luck's importance sap our motivation to try?

Has science gotten slower over the years? Does the proliferation of jargon make it harder for scientists to collaborate? What unstated assumptions -- "ghost theories" -- are shaping our research without us even realizing it? In this episode of Rationally Speaking Julia talks with sociologist of science James Evans, who investigates questions like these using some clever data mining.

If people don't have free will, then can we be held morally responsible for our actions? And what would happen to society if we were to collectively shed our belief in free will? In this episode Julia talks with philosopher Gregg Caruso, who advocates a position of "optimistic skepticism" on the topic. Skepticism because people don't have free will as a sense of moral responsibility, but optimistic because society would be better off if we accept that we do.

Naturalism is the stance that everything that exists in the universe arises from "natural" causes, of the sort observable by science -- not supernatural ones. It's practically a foundational tenet of skepticism. But does it imply that there can be no meaning, or purpose, or morality in the universe? This episode features physicist Sean Carroll, author of the recent bestseller The Big Picture: on the Origins of Life, Meaning and the Universe Itself. Sean and Julia talk about the new "ism" he introduces in the book, "poetic naturalism," and how it attempts to resolve the apparent conflict between science on the one hand, and things like morality, free will, consciousness, and meaning on the other.

Julia chats with the authors of Algorithms to Live By, about how to apply key algorithms from computer science to our real life problems. For example, deciding which apartment to rent, planning your career, and prioritizing your projects. In the process, they discuss the assumptions that underlie those algorithms (and what to do about the fact that those assumptions are inevitably violated by the messy real world), and why procrastination might actually be the right algorithm for the wrong problem.

It's the annual live Rationally Speaking episode, taped at the Northeast Conference on Science and Skepticism in NYC! This year features returning guest Jacob Appel, a bioethicist (and lawyer, and psychiatrist). Jacob and Julia discuss various bioethical dilemmas, such as: How do you handle parents who want to withhold medical treatment from their child for religious reasons? Is it unethical for American doctors to test new medications in the third-world? And what kinds of principles does a bioethicist use to justify their decisions, beyond "that's just my personal opinion"?

In this episode Julia talks with philosopher of cognitive science Colin Allen about whether fish can feel pain. In the process they explore a cluster of related questions: Are fish conscious, and how could we tell? What's the difference between pain and suffering? And are there evolutionarily adaptive reasons why animals would have the subjective experience of pain, as opposed to just instinctive reflexes to avoid potentially harmful stimuli?

Ever make a plan to diet, or exercise, or study, and then -- when the scheduled hour rolls around -- decide, "Nah, I'll just put it off another day"? If you said "no," I don't believe you! This episode features behavioral psychiatrist (and economist) George Ainslie, who demonstrated the existence of this ubiquitous phenomenon in human willpower, called hyperbolic discounting, in which our preferences change depending on how immediate or distant the choice is. George and Julia discuss why hyperbolic discounting exists, and how it can be modeled as a negotiation between your current self and your future selves. In the process they explore some of the benefits and risks of this "intertemporal bargaining" approach to willpower, and how it relates to philosophical thought experiments such as the Prisoner's Dilemma and Kavka's Toxin.

For centuries, scientists have wondered what makes humans so much smarter than other species. Some proposed it was the size of our brain (though that didn't explain why whales weren't smarter than us); others thought it was the size of our brain relative to our body size (but there were problems with that explanation as well). In this episode, neuroscientist Suzana Herculano-Houzel lays out the mystery of the "Human advantage," and explains how a new technique she invented several years ago has shed light on some of these longstanding mysteries.

You're probably already aware that it's hard to change someone's mind with logical arguments and evidence, especially about emotionally charged topics. But are there exceptions? David McRaney, bestselling author of "You Are Not So Smart" (and host of the blog and podcast by the same name) describes his experiences with people who have done an about-face on some important topic, like 9/11 conspiracy theories. He and Julia discuss a technique for changing someone's mind with evidence, how individual mind-change mirrors scientific progress, and what happens when you confront Trump fans with facts that contradict their narrative.

He's been called a "Data vigilante." In this episode, Prof. Uri Simonsohn describes how he detects fraudulent work in psychology and economics -- what clues tip him off? How big of a problem is fraud relative to other issues like P-hacking? And what solutions are there?

You've probably heard about cognitive biases -- the systematic errors human brains make when we try to reason or make decisions. But what if our biases are actually a sign of rationality? This episode features Tom Griffiths, professor of cognitive science at University of California, Berkeley and the director of the Computational Cognitive Science lab. Tom makes the case for why our built-in reasoning strategies might be optimal after all.

We like to think of doctors as experts, whose recommendations are backed up by solid evidence. So why does it keep happening that a widely used medical intervention -- like estrogen replacement therapy, or heart stents -- turns out to be useless, or even harmful? This episode features Dr. Vinay Prasad, author of "Ending Medical Reversal: Improving Outcomes, Saving Lives," who talks with Julia about why medical research is so often fatally flawed, and what we can do about it.

Julia invites philosopher and blogger Dan Fincke onto the show, inspired by a productive disagreement they had on Facebook. Their topic in this episode: civility in public discourse. Do atheists and skeptics have a responsibility to be civil when expressing disagreement, and does that responsibility vary depending on who their target is? Is there a legitimate role for offensive satire? And might there be downsides to civility? Dan and Julia also revisit the subject of their original disagreement: the recent NECSS decision to rescind Richard Dawkins' speaking invitation, on account of a video he tweeted which compared feminists to Islamists. Dan and Julia attempt to put the Dawkins case study in the broader context of the civility debate, asking questions like: What makes something offensive, and can someone be *unjustifiably* offended?

You've probably heard about victims of con artists -- like the people who hand over their life savings to sketchy gurus or psychics, or the people who wire thousands of dollars to a "Nigerian prince" who just needs some help getting his far bigger fortune to you. And you've probably thought to yourself, "What a sucker. I'd never fall for something like that." But are you sure? In this episode of Rationally Speaking, Julia interviews Maria Konnikova, science journalist and author of "The Confidence Game: Why we fall for it... Every time," who explains why con artists are so effective that even the best of us are vulnerable. Along the way, they explore questions like: Why do people refuse to believe they've been conned? Are con artists getting more sophisticated over time? And how do con artists view themselves -- do they rationalize their actions, or are they impassive sociopaths?

Do you remember when you were a kid, and you had that great day at Disneyland where you got to meet Bugs Bunny? No? Think harder. It was a sunny day... In this episode of Rationally Speaking, Julia interviews psychologist Elizabeth Loftus, whose pioneering work on human memory revealed that our memories can be contaminated by the questions people ask us, or by misinformation we encounter after the fact -- even to the point of making us remember entire events that never could have happened. (Like meeting Bugs Bunny, a Warner Bros character, at Disneyland.)

In this episode, psychologist Susan Gelman describes her work on the psychological trait of essentialism: the innate human urge to categorize reality and to assume that those categories reflect meaningful, invisible differences. Julia and Susan discuss why the discovery of essentialism in children was such a surprise to scientists, how the language we use affects the way we view reality, and whether essentialism is to blame for bad philosophy.

We're all familiar with Santa Claus -- but how much do you *really* know about that jolly old elf? In this episode, Julia interviews philosophy professor David Kyle Johnson, the author of "The Myths that Stole Christmas." Kyle explains the little-known, and somewhat sinister, origin story of Santa Claus -- and then Kyle and Julia debate whether it's ethical to lie to your children about the reality of Santa Claus (and possible alternatives to explore).

There are two contradictory stories about politics and class: On the one hand, that the Republicans are the party of the fat cat businessmen and the Democrats are the party of the people. And on the other hand, that the Republicans are the party of the salt-of-the-earth Joe Sixpacks, while the Democrats are latte-sipping elites. In this episode, professor of statistics and political science Andrew Gelman shines some clarifying light on the intersection between politics and class in America, explaining what the numbers really show. He and Julia also cover the question, "Is it rational to vote?"

This episode of Rationally Speaking features Jesse Richardson, a creative director who has been using his advertising background "for good and not for evil," as he puts it -- by building skeptic sites that go viral. Jesse's most famous creation is "Your Logical Fallacy Is," an illustrated poster featuring the names and descriptions of various common fallacies. Julia asks: Aren't many so-called logical fallacies not actually fallacious? Is encouraging people to call out fallacies helping rational discourse overall, or harming it? And is there a trade-off between accuracy and virality?

Most people are terrible at predicting the future. But a small subset of people are significantly less terrible: the Superforecasters. On this episode of Rationally Speaking, Julia talks with professor Phil Tetlock, whose team of volunteer forecasters has racked up landslide wins in forecasting tournaments sponsored by the US government. He and Julia explore what his teams were doing right and what we can learn from them, the problem of meta-uncertainty, and how much we should expect prediction skill in one domain (like politics or economics) to carry over to other domains in real life.

Parents in the United States are spending more time and energy than ever to ensure that their children turn out happy, healthy, and successful. But what does the evidence suggest about the impact of their efforts? Economist Bryan Caplan (and the author of "Selfish Reasons to Have More Kids") argues that, despite our intuition that parenting choices affect children's life outcomes, there's strong evidence to the contrary. Bryan and Julia discuss his case, and explore what that means for how people should parent and how many kids they should have.

Can rational people disagree? This episode of Rationally Speaking features guest Scott Aaronson. Scott is a professor of computer science at MIT and has written about "Aumann's Agreement Theorem," which is related to Bayesian probability theory and seems to imply that two people cannot rationally disagree after they've shared their opinions and information with each other. Julia and Scott discuss how to reconcile Aumann's theorem with real-world disagreements, and explore the disconcerting question: Why should you favor your own beliefs, just because they're yours?

"I'm writing a book on empathy," psychologist Paul Bloom tells people. They respond warmly, until he follows up with, "I'm against it." On this episode of Rationally Speaking, Julia and Paul discuss what empathy is, why Paul is concerned that it's a terrible guide to moral decision making, and what the alternatives are.

The traditional story about reason is that it evolved to help humans see the world more clearly and (thereby) make better decisions. But on that view, some mysteries remain: why is the human brain so biased? Why are we so much better at defending our pre-existing views than at evaluating new ideas objectively? In this episode of Rationally Speaking, Julia talks with guest Dan Sperber, professor of cognitive and social sciences, who is famous for advancing an alternate view of reason: that it evolved to help us argue with our fellow humans and convince them that we're right. Dan Sperber is a social and cognitive scientist. His most influential work has been in the fields of cognitive anthropology and linguistic pragmatics. Sperber currently holds the positions of Directeur de Recherche émérite at the Centre National de la Recherche Scientifique and Director of the International Cognition and Culture Institute.

This episode of Rationally Speaking features philosopher Kenny Easwaran, who delves into the notorious "Newcomb's Paradox" -- the puzzle about which it was once said, "To almost everyone it is perfectly clear and obvious what should be done. The difficulty is that these people seem to divide almost evenly on the problem, with large numbers thinking that the opposing half is just being silly." Kenny and Julia explore how Newcomb's Paradox is related to other puzzles in decision theory, like the Prisoners' Dilemma; what its implications are for free will; and what Kenny calls the "deep tragedy" at the heart of rationality. Kenny Easwaran is an Associate Professor in the Philosophy Department at Texas A&M University. He works on several topics relating to epistemology and decision theory, and the role of probability in helping to understand these and related concepts.

You might expect that professional ethicists -- people whose job it is to determine which behaviors are ethical and why -- would behave more ethically than other people. You'd be wrong! This episode features philosopher Eric Schwitzgebel , who is well known for his work studying whether experts in ethics live up to their own standards. He and Julia discuss why the answer is "no," and explore questions like, "How do you decide how moral you're going to try to be?" Eric Schwitzgebel is a Professor of Philosophy at University of California at Riverside. He is the co-author (with Russell T. Hurlburt) of Describing Inner Experience?: Proponent Meets Skeptic and blogs at The splintered Mind.

For several centuries, historians have tried to answer the question: "Why is Western Europe (and later, North America) the dominant world power?" Past explanations cited culture, or "great men" who influenced the course of history. Stanford historian Prof. Ian Morris casts doubt on those explanations, instead taking a data-driven approach to the question that attempts to measure "social development" over history and find explanations for it. In this episode of Rationally Speaking, Julia delves into Morris' method and conclusions, and asks: can we make causal inferences about history? Ian Morris is Willard Professor of Classics and Fellow of the Archaeology Center, Stanford University. He is a historian and archaeologist. He has excavated in Britain, Greece, and Italy, most recently as director of Stanford's dig at Monte Polizzo, a native Sicilian site from the age of Greek colonization. He is also the author of a number of books, among them: "Why the West Rules--for Now". "War! What Is It Good For?", and "Foragers, Farmers, and Fossil Fuels."

A controversial field of research is "gain-of-function," in which scientists take a virus (like a strain of flu) and attempt to make it more dangerous, for example by making it transmissible in mammals when it had previously been solely an avian flu. The motivation is to learn how viruses might mutate in nature so that we can be prepared -- but what if those engineered "superbugs" escape the lab and start a pandemic? In this episode of Rationally Speaking, Harvard professor of epidemiology Marc Lipsitch argues that the risks outweigh the benefits, and that we should halt gain-of-function research as soon as possible. Marc Lipsitch is Professor of Epidemiology with primary appointment in the Department of Epidemiology and a joint appointment in the Department of Immunology and Infectious Diseases. He directs the Center for Communicable Disease Dynamics, a center of excellence funded by the MIDAS program of NIH/NIGMS. He is also the Associate Director of the Interdisciplinary Concentration in Infectious Disease Epidemiology.

Can we pull the world's poor out of poverty by giving them access to financial services? This episode features a conversation with economist David Roodman, formerly a fellow at the Center for Global Development and senior advisor to the Gates Foundation, currently senior advisor to the Open Philanthropy Project, and the author of Due Diligence: An Impertinent Inquiry into Microfinance. Roodman casts a critical eye on the hype about microfinance as a panacea for global poverty. He and Julia explore why it's hard to design a good study, even a randomized one; three different conceptions of "development,"; and why Goodman doesn't think we should give up on microfinance altogether.

In this episode, economist Robin Hanson explains the signaling theory of human behavior: That our motivations for our choices, about school, shopping, medical care, and so on, evolved primarily to shape other people's perceptions of us. In the process Robin and Julia discuss what makes a good theory: How to decide what you should (a priori) expect to see, and why simplicity is a virtue. Robin Dale Hanson is an associate professor of economics at George Mason University and a research associate at the Future of Humanity Institute of Oxford University. He is known as an expert on idea futures and markets, and he was involved in the creation of the Foresight Exchange and DARPA's Future MAP project. he blogs at Overcomng Bias.

Common wisdom holds that the world is getting more violent, but is that really true? Leading skeptic Michael Shermer, professor and author of many books on science, morality and skepticism, argues to the contrary. Shermer's thesis in his recent book, "The Moral Arc: How Science Leads Humanity Toward Truth, Justice, and Freedom," is that as science has advanced our understanding of the world, we have become more willing to expand our circle of empathy beyond our own provincial "tribes," and more able to design our societies to encourage human flourishing. Dr. Michael Shermer is the Founding Publisher of Skeptic magazine, a monthly columnist for Scientific American, a regular contributor to Time.com, and Presidential Fellow at Chapman University. His new book is The Moral Arc: How Science and Reason Lead Humanity Toward Truth, Justice, and Freedom.

In this episode of Rationally Speaking, Caltech physicist Sean Carroll describes an "embarrassing" state of affairs in modern physics: that we still don't know how to interpret quantum mechanics, almost a century after its discovery. Sean explains why he thinks the "Many Worlds Interpretation" (MWI) is the most plausible one we've got, and Julia explores his thoughts on questions like: Can MWI be tested? Is it "simpler" than other interpretations, and why? And does MWI threaten to destroy our systems of ethics? Sean Michael Carroll is a research professor in the Department of Physics at the California Institute of Technology. He is a theoretical cosmologist specializing in dark energy and general relativity.

This live episode of Rationally Speaking, taped at the 2015 Northeast Conference on Science and Skepticism, is a special one: it's Massimo's last episode as co-host! He and Julia look back over their history together and discuss which topics they've changed their mind about since the podcast began.

The Amazing Randi, famous magician and a pioneer of Skepticism, joins this episode of Rationally Speaking for a conversation about the past and future of the Skeptic movement. Massimo and Julia's questions for Randi include: Do you think Skepticism has shaped public opinion in any significant ways? What do you want the JREF to look like several years from now? And what have you changed your mind about, and why?

Do atheists need their own 10 commandments? What would such a thing look like? In this episode, Julia and Massimo discuss a recent attempt to define some secular commandments. They debate the relevance of particular commandments, like "All truth is proportional to the evidence," and the purpose of the project overall, and address some criticism of the commandments.

Atheists often take it as a given that the world would be better off without religion. But what does the evidence so far really say? In this episode, Massimo and Julia discuss a recent article in the Skeptical Inquirer presenting research that shows a moderate correlation between religiosity and prosocial traits like altruism. Should we doubt the research? And if not, are there other reasons to suspect that religion's net effect on the world is negative?

This episode marks the fifth anniversary of the Rationally Speaking podcast! To commemorate the occasion, Massimo and Julia hold a live-streaming Q&A in which they respond to questions submitted via Twitter. Topics include: What's the best book to read to improve your rationality? What's the biggest problem with the skeptic community? How can we get politicians to be reasonable? And how can you be so sure that other people exist? Halfway through the show, Massimo makes a surprising and poignant announcement.

Feynman famously said that a philosopher of science is as much use to scientists as an ornithologist is to birds. This episode of Rationally Speaking features philosopher of physics Elise Crull, who explains why Feynman is misguided, and what philosophers have to say about important issues in physics -- like quantum mechanics, physical laws, and whether anything "really" exists at all.

Can it be rational to believe conspiracy theories? On this episode of Rationally Speaking, Julia and Massimo welcome Prof. Preston Bost, a professor of psychology at Wabash College who investigates what kinds of people latch onto conspiracy theories, and why. The three discuss evolutionary reasons for conspiracy theories' appeal, and ask: how do you determine whether a belief is "rational," anyway?

People have been keeping track of their moods, sleeping, dietary habits and more for hundreds of years -- Benjamin Franklin famously recorded instances of his virtues and vices. But only in the last decade has the rise of smartphones and fast computing created the new "Quantified Self" movement in which some people are trying to mine their own data for insights about how to be happier and more effective. In this episode, Massimo and Julia discuss self tracking -- what you can learn from it, and what its pitfalls might be.

Did you miss International Stoic Week this year? Well, it's not too late to catch Massimo and Julia's analysis of the ancient philosophy of stoicism, which advocates (among other things) practicing mindfulness, accepting the things you can't change, and regulating negative emotions. Come hear the results of Massimo's experimentation with stoicism and listen to him and Julia debate several potential problems with the philosophy.

What's wrong with the social sciences? In this episode, Massimo and Julia are joined by Professor Daniel Lakens from the Eindhoven University of Technology, who studies psychology and blogs about research methods and open science. The three discuss why so many psychology papers can't be trusted, and what solutions might exist for the problem (including how to fix the skewed incentives in the field).

In this episode of Rationally Speaking, Massimo and Julia delve into the science and philosophy of comedy, exploring questions like: Why did humans evolve to have a sense of humor? What's the relationship between comedy and existential terror? And how many bad philosophy jokes can Massimo tell before Julia loses it entirely?

If you want to choose a career that helps other people effectively, which should you pick? Medicine? Research? Non-profit? The answers may not be as straightforward as you think. This episode of Rationally Speaking features special guest Benjamin Todd, the co-founder and executive director of 80,000 Hours, an organization devoted to helping people choose career paths to do good better. Ben, Massimo and Julia debate the heuristics that should go into career choice, utilitarianism vs. virtue ethics, and what exactly we mean by "doing good."

Are you a nihilist? Forget about wearing all black and being indifferent to the rest of the world -- nihilism is a lot more complicated than most people think. In this episode of Rationally Speaking, Massimo and Julia explain the different types of philosophical nihilism, reveal their own personal views on the subject, and explore why nihilism has such different emotional effects on different people.

You probably feel like you can recognize someone who's an asshole when you're unlucky enough to encounter him. But can you really? Philosophy professor Aaron James, the author of "Assholes: A Theory," joins the podcast to lay out just what makes an asshole an asshole, and why they're so uniquely maddening. Massimo, Julia and Aaron debate the assholery of certain people in politics and atheism, explore the difference between an asshole and a bitch, and swap coping mechanisms.

Taped in front of a live audience at Baruch College in New York, this episode of Rationally Speaking features special guest Steve Novella: neurologist, author of the blogs NeuroLogica and Science Based Medicine, and co-host of the Skeptic's Guide to the Universe (SGU) podcast. Steve, Massimo, and Julia discuss the recent lawsuit facing the SGU, share their gripes about the ways that skeptics sometimes oversimplify the issues, and answer audience questions such as, "Is anything off-limits to skeptical activism?"

Want to learn how to use your logical, reflective side in everyday life? It's elementary, my dear listeners! Maria Konnikova, the author of the bestselling Mastermind: How to Think Like Sherlock Holmes is the special guest on this episode of Rationally Speaking. Konnikova has a Ph.D. in psychology from Columbia University and writes about science for publications including the New Yorker, New York Times, Wall Street Journal, and more. Julia and Massimo ask her for tips on Holmesian thinking, and debate her on questions like: Is your unreflective, "Watsonian" side really so bad? And did Sherlock make some mistakes in his famous quotes about thinking?

As part of our special mini-interviews series, Massimo talks to Jim Baggott, author of “Farewell to Reality: How Modern Physics Has Betrayed the Search for Scientific Truth.” Jim is one of an increasingly vocal number of critics of some directions taken lately by research in fundamental theoretical physics, and particularly of string theory. Massimo and Jim explore what it means for some physicists to call for a new era of “post-empirical” science.

In our first mini-interview episode Massimo sits down to chat with his colleague Maarten Boudry, a philosopher of science from the University of Ghent in Belgium. Maarten recently co-edited the volume on The Philosophy of Pseudoscience (Chicago Press) with Massimo, and the two chat about the difference between science and pseudoscience and why it is an important topic not just in philosophy circles, but in the broader public arena as well.

In this special episode of Rationally Speaking, Julia and Massimo go rogue: no guest, no pre-set topics, just conversation about things on their mind. Among other things, the duo discuss the questions of how to change your mind (Julia describes her "surprise journalling" method) and, importantly: How do you know if you're a jerk?

Did you know that an artificial intelligence named "Eugene Goostman" recently passed the Turing Test, our gold standard criterion for whether an AI is conscious? At least, that's what many media outlets breathlessly reported. In this episode of Rationally Speaking, Julia and Massimo take a critical look at Eugene, and at the Turing test in general as a standard for consciousness. In the process they debate what it would mean for an AI to be conscious, and how we could ever tell.

In this episode, Julia and Massimo talk about the problems with "race" as a genetically-based concept. Starting with the controversial recent book "A Troublesome Inheritance," by NY Times science writer Nicholas Wade, they critique the statistical analyses that group people into racial categories, and Wade's (and others') attempts to attribute differences between rich and poor countries to innate racial differences.

Ever heard someone sigh, "That's just human nature"? Have you wondered what that meant? In this episode of Rationally Speaking, Julia and Massimo delve into the science and philosophy of human nature: what traits are "built in" to being human, and how would we know? And once we know what human nature consists of, should we try to protect it against changes?

For all the sniping that goes on between science and philosophy it's easy to forget that both fields are part of "scientia," the pursuit of knowledge and understanding. In this episode of Rationally Speaking, Julia and Massimo discuss the latter's new "Scientia Salon" online journal, how the boundaries blur between math, science and philosophy, and how the Internet can change scientific research.

Rebecca Newberger Goldstein -- philosopher, author, and Genius-grant recipient -- returns to the Rationally Speaking podcast to discuss her latest book, "Plato at the Googleplex: Why Philosophy Won't Go Away." Rebecca, Julia and Massimo argue over the value of philosophy in modern science, and whether it makes sense to designate "experts" in ethical reasoning.

"There is but one truly serious philosophical problem, and that is suicide," wrote Albert Camus. In this episode of Rationally Speaking, Massimo and Julia discuss the ethics of suicide through the lens of several major philosophies. They also explore the social science of suicide: how does one person's suicide affect the community?

Does the future belong to MOOCs? Massive Open Online Courses, or MOOCs for short, have been hailed as the next wave in secondary education, poised to replace brick-and-mortar colleges with their expensive infrastructure and sky-high tuition. In this episode of Rationally Speaking, Julia and Massimo discuss how to measure MOOCs' effectiveness, separating the hype from the genuine promise.

Rationally Speaking returns to NECSS for a live show with Lawrence Krauss, theoretical physicist and author of best selling books like The Physics of Star Trek and A Universe from Nothing. Julia and Massimo chat with Lawrence about whether the laws of the universe demand some kind of explanation, whether string theory should be deemed a failure, and how he ended up featured in a geocentrist documentary.

Atheist activist and author Greta Christina appears on this episode of Rationally Speaking, to discuss her new book, "Coming Out Atheist: How to Do It, How to Help Each Other, And Why." A spirited debate ensues, in which Greta, Julia and Massimo disagree over the boundaries of the "atheist movement," and the role of social justice in it. Other topics include: The cognitive biases that can make it hard to get a clear picture of whether people regret "coming out" as atheists; Plus, Greta's argument for why atheist community-building shouldn't model itself after religious communities.

Can you find beauty -- even romance -- in mathematics? Mathematician Edward Frenkel, author of "Love and Math," joins Rationally Speaking to talk about how the subject seduced him as a young man, and how he believes it's generally mis-taught in schools. Other topics include: the search for a "grand unified theory" of mathematics, and the splash Edward caused when he produced -- and starred in -- "Rites of Love and Math," a steamy short film about equations.

Astrophysicist Neil deGrasse Tyson returns for this episode of Rationally Speaking, with a particular question to discuss: Should he call himself an atheist? The impetus is a recent dust-up over Neil's appearance on Big Think, in which he explained that he avoids the label "atheist" because it causes people to make all sorts of unflattering (and often untrue) assumptions. Julia and Massimo reply with some counterarguments, and along the way delve into the philosophy of language.

This episode features special guest Zach Weinersmith, author of "Saturday Morning Breakfast Cereal," a popular webcomic about philosophy and science. Zach clarifies his position in the ongoing "philosophy vs. science" fight, poses a question to Julia and Massimo about the ethics of offensive jokes, and discusses BAHFest, his "Bad Ad Hoc Hypotheses" conference lampooning evolutionary psychology and his movie "Starpocalype." Somehow along the way, the three take a detour into discussing an unusual sexual act.

Those among us who loathed high school calculus might feel some trepidation at the premise in this week's episode of Rationally Speaking. MIT Physicist Max Tegmark joins us to talk about his book "Our Mathematical Universe: My Quest for the Ultimate Nature of Reality" in which explains the controversial argument that everything around us is made of math. Max, Massimo and Julia explore the arguments for such a theory, how it could be tested, and what it even means.

On this episode, recorded live at the Jefferson Market Library in New York City, Rationally Speaking podcast celebrates its 100th episode! The show features a full hour of audience Q’s and Julia & Massimo’s A’s. Topics range from science, philosophy and the borderlands between the two. The questions push the hosts to think on their feet, and even to admit their ignorance on stage!

Creative geniuses are always a little bit cuckoo, right? At least, that's the impression you'd get from TV, movies, and plenty of common wisdom. In this episode of Rationally Speaking, Massimo and Julia are joined by psychologist Judith Schlesinger, author of The Insanity Hoax: Exposing the Myth of the Mad Genius, who explains why she thinks the "mad genius" archetype is simply the result of folklore, misunderstanding, and bad research.

What qualifies someone as mentally ill? The standard for diagnosis is the Diagnostic and Statistical Manual of Mental Disorders (DSM), which just released a 5th edition in 2013 -- but just how objective is it? This episode of Rationally Speaking features Dr. Jerome Wakefield, psychiatrist, PhD in philosophy, and author of "The Loss of Sadness: How Psychiatry Transformed Normal Sorrow into Depressive Disorder." Julia, Massimo and Jerome talk about the arbitrariness of the DSM and the controversies around the boundaries of various mental disorders, including depression and sexual fetishes.

Few philosophers have as wide of an impact on the general public as ethicist Peter Singer, this week's guest on Rationally Speaking podcast. Singer's utilitarian arguments about how we should treat animals, why we have a moral obligation to give to charity, whether infants should count as "people," and more have won him widespread fame -- and notoriety -- over the last few decades, and launched multiple movements. Tune in to hear his discussion with Massimo and Julia about why he's a utilitarian, and how his views of utilitarianism have recently changed (and find out how he influenced Massimo's life years ago).

It seems like a week can't go by without a news story about how neuroscience has discovered the neurological basis of love, morality, addiction, you name it. Yet how much explanatory power does neuroscience really have -- and are we putting too much trust in its findings? On this episode of Rationally Speaking, Massimo and Julia explore these questions with psychiatrist Sally Satel and professor of psychology Scott O. Lilienfeld, the authors of "Brainwashed: The Seductive Appeal of Mindless Neuroscience."

Is the mind a kind of computer? This episode of Rationally Speaking features philosopher Gerard O'Brien from the University of Adelaide, who specializes in the philosophy of mind. Gerard, Julia, and Massimo discuss the computational theory of mind and what it implies about consciousness, intelligence, and the possibility of uploading people onto computers.

What's the difference between science and pseudocience -- and is it even possible to draw a clean line separating them? In this episode of Rationally Speaking, Massimo and Julia interview philosopher Maarten Boudry from Ghent University. Tune in to hear them discuss Massimo and Maarten's new book, "Philosophy of Pseudoscience: Reconsidering the Demarcation Problem"... and stick around to learn how Maarten pranked theologians.

In this episode of Rationally Speaking, Julia and Massimo talk to physicist and climatologist Michael Mann about how we know the climate is getting warmer. Among other things, they cover the physical processes of climate change, the role that predictive models have played in confirming scientists' theories about the rate of warming, and what are uncertainties in the science. Also, how optimistic we should be about technological solutions to the problem. Dr. Michael E. Mann is Distinguished Professor of Meteorology at Penn State University, with joint appointments in the Department of Geosciences and the Earth and Environmental Systems Institute. He is also director of the Penn State Earth System Science Center. Dr. Mann is author of more than 160 peer-reviewed and edited publications, and has published two books including Dire Predictions: "Understanding Global Warming in 2008 and The Hockey Stick and the Climate Wars: Dispatches from the Front Lines" in 2012. He is also a co-founder and avid contributor to the award-winning science website RealClimate.org.

How has alternative medicine managed to become so mainstream? This episode of Rationally Speaking features Dr. Paul Offit, award-winning specialist in vaccines, immunology and pediatrics, and author of popular books such as "Do You Believe in Magic?: The Sense and Nonsense of Alternative Medicine." Julia and Massimo interview Dr. Offit about the fight against alternative medicine, why it's still unregulated, and whether or not to tell patients about placebos.

On this episode of Rationally Speaking, Massimo and Julia survey the present, past, and future of skepticism. Special guest Kendrick Frazier, editor of Skeptical Inquirer, talks about how the movement's focus has changed and what the frontiers of skepticism should be. Kendrick Crosby Frazier is a science writer and editor of Skeptical Inquirer magazine for over 30 years. He is also a former editor of Science News, author or editor of ten books, and a Fellow of the American Association for the Advancement of Science.

In this episode of Rationally Speaking, Julia and Massimo turn their attention to connoisseurship -- or snobbery, depending on your point of view! Fine wines, bottled water, high-end audio equipment -- what all these have in common are passionate customers who are discriminating enough to pay top dollar for subtle differences between options. Or are they? This episode explores the evidence on whether connoisseurs can really tell the difference between, for example, the $7 wine and the $700 one -- or whether it's a distinction without a difference.

Looking for love online? You're not alone -- one in five new relationships nowadays begin on a dating site. But just how scientific are the "matching algorithms" sites like eHarmony and OKCupid use? What does cognitive psychology tell us about how this new choice context affects our happiness? Massimo and Julia turn an analytical eye on the math and science of online dating, in this episode of Rationally Speaking.

The next time you're kicking yourself for some stupid mistake, remember: Even history's genuises screw up! Astrophysicist and author Mario Livio joins this episode of Rationally Speaking to talk about his latest book, "Brilliant Blunders: From Darwin to Einstein - Colossal Mistakes by Great Scientists That Changed Our Understanding of Life and the Universe." Learn about why Darwin's theory of natural selection "shouldn't" have worked, why Einstein was confused about the role of aesthetics in physics, why Hoyle stubbornly refused to change his mind about a "steady state" universe -- and why those mistakes are central to scientific progress.

Astrophysicist and author Sean Carroll joins this episode of Rationally Speaking, to talk about "naturalism" -- the philosophical viewpoint that there are no supernatural phenomena, and the universe runs on scientific laws. Sean, Julia, and Massimo discuss what distinguishes naturalism from similar philosophies like physicalism and materialism, and what a naturalistic worldview implies about free will, consciousness, and other philosophical dilemmas. And they return to that long-standing debate: should scientists have more respect for philosophy?

Why does the universe exist? And is that even a sensical question to ask? Philosopher Jim Holt has written extensively for publications such as the New Yorker, the New York Times and Harper's, and most recently embarked on this "existential detective story" in his new book, "Why Does the World Exist?: An Existential Detective Story" Jim discusses his book with Massimo and Julia in this live episode of Rationally Speaking, taped at the 2013 Northeast Conference on Science and Skepticism in New York City.

In a special live Rationally Speaking, taped at NECSS 2013, Julia Galef moderates a lively discussion between Massimo and Michael Shermer, head of the Skeptic Society and founding publisher of Skeptic Magazine. The topic: Can science tell us what is "moral"? This discussion comes after both men have tackled the question separately in books (Massimo's Answers for Aristotle and Michael's The Science of Good and Evil), and jointly in a recent debate on the Rationally Speaking blog. Questions under debate include: Does "natural" = "morally right"? How do we make tradeoffs between different people's happiness? And what role should science and philosophy play in making these decisions?

Just like love, motherhood, and apple pie, no one could be against fairness. No one, that is, except philosopher Stephen Asma, the author of "Against Fairness." Massimo and Julia sit down with Stephen in this episode of Rationally Speaking, to talk about what he thinks is wrong with the concept of fairness -- and about certain traditional values he thinks are more important.

How long does it take for one-half of everything we know about a subject to be proven wrong? Depends on the subject. 45 years, for example, if that subject is cirrhosis or hepatitis. Samuel Arbesman, applied mathematician and author of "The Half-Life of Facts: Why Everything We Know Has an expiration Date", joins Julia and Massimo to talk about the hidden patterns underlying how fast our understanding of science is changing.

If you're an ethically minded consumer, you should buy organic because it's better for the environment, right? Actually, the case isn't so clear-cut. But you should certainly buy fair-trade because it's better for foreign laborers, right? Well... that's complicated too. In this episode of Rationally Speaking, Julia and Massimo talk about how hard it is to know how much good you're accomplishing with your purchases, or whether you're even doing any good at all.

"Medicine is broken," warns Ben Goldacre, the British physician, academic, author of the Guardian's Bad Science column. In this live episode of Rationally Speaking, Massimo and Julia interview Ben about his new book, Bad Pharma, and how the evidence about pharmaceutical drugs gets distorted due to shoddy regulations, missing data, and the influence of drug companies.

In honor of the passing of Dear Abby columnist Pauline Philips, Massimo and Julia talk about the history and philosophy of advice. How do you rationally evaluate advice, and how do you give rational advice? Along the way they discuss some of Dear Abby's snarkiest moments, the origins of the advice column in 1680, and some of the worst advice ever given.

Can science denialism be blamed on a "Republican brain"? In other words: is there something about the psychology of Republicans that makes them inclined to reject the scientific consensus on topics like evolution and climate change? Special guest Chris Mooney argues there is, elaborating on the thesis in his popular book, "The Republican Brain: The Science of Why They Deny Science- and Reality." Massimo and Julia debate whether the evidence support Chris's thesis.

What's your IQ? Are you an ENTJ, or maybe an ISFP? What's your Openness score, your Conscientiousness score, your Neuroticism score? And just how seriously should you take all those test scores, anyway? In this episode of Rationally Speaking, Massimo and Julia discuss the science -- and lack thereof -- of intelligence and personality testing.

In this episode, Massimo and Julia discuss sociology and feminism, with special guest Victoria Pitts-Taylor, professor of sociology at the Graduate Center of the City University of New York. Victoria explains how feminists in sociology are dealing with results in neuroscience and evolutionary biology, especially regarding the question: How much inborn difference is there really between women and men? Massimo and Julia challenge Victoria on some academic feminist views, and investigate how the fields of sociology and academic feminism reach their conclusions -- what methods do they use, and how would we know if they were wrong?

What do Linux, Netflix, and the Oxford English Dictionary have in common? They've all benefited from the power of crowdsourcing, in which a task is outsourced to a group of hundreds or thousands of disparate people. In this episode of Rationally Speaking, Julia and Massimo discuss the phenomena of crowdsourcing, and ask: What makes it work? Is it ever unethical? And what are the limits to the wisdom of crowds?

We look to scientists to keep us informed about risks, such as: is this medicine effective? Is that level of toxicity harmless? How severe should we expect this upcoming storm to be? But when lives are at stake, tricky questions arise about how much responsibility falls on scientists' shoulders to get those estimations *right* -- and whether scientists should be punished if they fail. In this episode of Rationally Speaking, Massimo and Julia discuss a recent court case that shocked the world: A group of Italian scientists were sentenced to 6 years in prison for failing to effectively warn the public of an earthquake that killed over 300 people in 2009. Was this decision fair? And how should we decide where the boundaries of scientific accountability lie?

Massimo and Julia visit Indianapolis for a heated debate, in this live episode of Rationally Speaking. At a symposium organized by the Center for Inquiry (CFI), they join up with John Shook, Director of Education and Senior Research fellow at the CFI, and the author of more than a dozen books on philosophy and religion. Sparks fly as the three debate questions like: Should science-promoting organizations, like the National Center for Science Education, claim publicly that science is compatible with religion? And is philosophy incapable of telling us anything about the world?

In this episode Julia interviews Massimo about his new book, Answers for Aristotle: How Science and Philosophy Can Lead Us to A More Meaningful Life. Massimo's central idea is that a combination of science and philosophy, what he calls "Sci-Phi," is the best guide to the big questions in life, from issues of morality and justice to the meaning of love and friendship. The book's title derives from the fact that Aristotle was the first philosopher-scientist, adopting the sci-phi framework and posing a number of questions with which we are still struggling. What is the best way to live one's life? What sort of society do we want to live in? How do we relate to our friends and loved ones? Two and a half millennia later, modern science and philosophy have come up with some of the answers to Aristotle's questions, or at the least with a better way to think about them.

Can a statement be simultaneously true and false? That might seem like sheer nonsense to you -- but not to certain modern logicians. In this episode Massimo and Julia are joined again by philosopher and logician Graham Priest, who explains why we have to radically revise our notions of "true" and "false." In the process, he explains classic puzzlers like the "barber paradox": "In a village, the barber shaves all men who do not shave themselves. Does he shave himself?" Follow along for an episode that really takes to heart the podcast's tagline: exploring the borderlands between reason and nonsense.

By its very nature, science fiction has always been particularly suited to philosophical exploration. In fact, some of the best science fiction novels, short stories, movies, and TV shows function like extended philosophical thought experiments: what might cloning tell us about our views on personal identity? If we could all take a pill to be happy, would we want to do that? In this episode, Massimo and Julia recall some of their favorite philosophically-rich science fiction, and debate the potential pitfalls in using science fiction to reach philosophical conclusions.

For all the time Massimo and Julia have spent discussing and debating philosophy on Rationally Speaking, so far, it's all been philosophy from Europe and North America. What about the philosophical traditions of, for example, Asia? In this episode, professor of philosophy Graham Priest offers a brief introduction to the philosophy of India, China, and Japan, and explains why he thinks it should be better known in the West.

Compared to other fields of philosophy, "metaphysics" doesn't get a great rap -- it's both dauntingly obtuse and often derided as nonsense. In this episode of Rationally Speaking, Massimo and Julia chat with James Ladyman, Professor of philosophy at the University of Bristol and the author of Every Thing Must Go. The conversation covers: what is metaphysics, exactly, and where (in Ladyman's opinion) has it gone off the rails? Where does traditional science err in its classification of the "building blocks" of physics? What would a new, improved, metaphysics look like -- and what implications does that have for age-old questions like "What is causality?" and "Is the world real?"

You've heard plenty about biases: the thinking errors the human brain tends to make. But is there anything we can do to make ourselves *less* biased? In this episode, Massimo and Julia discuss what psychological research has learned about "de-biasing," the challenges involved, and the de-biasing strategies Julia is implementing at her organization, the Center for Applied Rationality.

Can everyone's problems always be traced back to sex, love, and masturbation? In this episode, Massimo and Julia talk about the pseudoscientific aspects of Freud's theories of human psychology. Along the way they explore what philosophy of science has to say about testing theories -- and some of the similarities that Freudianism has with religion, new age mysticism, and psychic reading.

You may think you're a skeptic, but are you really as free from superstition as you think you are? Matthew Hutson thinks not. The author of "The Seven Laws of Magical Thinking" joins Massimo and Julia on this episode of Rationally Speaking to discuss some common, innate forms of superstition that affect even self-identified skeptics, and why the human brain is predisposed to magical thinking. Along the way, the three debate: Overall, are our superstitions good for us?

Why do philosophers sometimes argue for conclusions that are disturbing, even shocking? Some recent examples include the claim that it's morally acceptable to kill babies; that there's nothing wrong with bestiality; and that having children is unethical. In this episode of Rationally Speaking, Massimo and Julia discuss what we can learn from these "Philosophical shock tactics," the public reaction to them, and what role emotion should play in philosophy.

Nature vs. Nurture? Massimo and Julia revive the age-old debate in this episode of Rationally Speaking, with special guest Jesse Prinz. Jesse is a professor of philosophy at CUNY and the author of several books, most recently "Beyond Human Nature." The trio debate Jesse's argument that human behavior is far more culturally determined than evolutionary psychologists would have you believe, and in the process explore the question of where morality comes from and how to distinguish between nature and nurture.

Will all knowledge eventually be united? And what does that even mean, anyway? In this episode of Rationally Speaking, Massimo and Julia explore the topic of consilience, or the "unity of knowledge," a concept popularized by biologist and theorizer E. O. Wilson. Along the way they discuss whether all phenomena can be explained in terms of physics, the importance of precise language, and the seductive dangers of the "deepity."

The Rationally Speaking podcast is proud to feature another certified genius: Patricia Churchland, a philosopher well known for her contributions to neurophilosophy and the philosophy of the mind, was professor at the University of California San Diego from 1984-2010, and won the MacArthur Genius Grant in 1991. In this episode, she, Massimo, and Julia discuss what philosophy has to say about neuroscience, what neuroscience has to say about philosophy, and what both of them have to say about morality.

This episode of Rationally Speaking is all about the age-old problem of willpower: why don't we do what we know is best for us? Massimo introduces some of the early philosophical approaches to this puzzle, and then Massimo and Julia go over more recent scientific research on the issue (for example: does resisting temptation deplete your reserves of willpower, or does it strengthen your willpower "muscle"?). They also examine possible solutions to the problem, including betting and precommitment, and online programs that can help.

Massimo and Julia answer listeners' questions. In this installment the topics include: how much do works of fiction affect people's rationality, Bayesian vs. frequentist statistics, what is evidence, how much blame do people deserve when their actions increase the chance of them being targeted, time travel, and whether a philosophically examined life is a better life. Also, all about rationality in the movies, from Dr. Who to Scooby-Doo.

In this special live episode recorded at the 2012 Northeast Conference on Science and Skepticism, Massimo and Julia discuss the "simulation argument" -- the case that it's roughly 20% likely that we live in a computer simulation -- and the surprising implications that argument has for religion. Their guest is philosopher David Kyle Johnson, who is professor of philosophy at King's College and author of the blog "Plato on Pop" for Psychology Today, and who hosts his own podcast at philosophyandpopculture.com. Elaborating on an article he recently published in the journal Philo, Johnson lays out the simulation argument and his own insight into how it might solve the age-old Problem of Evil (i.e., "How is it possible that an all-powerful, all-knowing, and good God could allow evil to occur in the world?"). As usual, Massimo and Julia have plenty of questions and comments!

When your intuition tells you something, should you listen? That depends! Relying on intuition can be anything from a highly effective strategy used by experts, to an excuse not to require evidence for your beliefs. In this episode, Massimo and Julia talk about what people mean by "intuition," where our intuitions come from, and when intuition can beat careful reasoning.

If you value scientific evidence you're probably familiar with the idea that having "peer-reviewed" studies is crucial to the legitimacy of any new claim. But what does "peer-reviewed" entail, anyway? In this episode, Massimo and Julia open up the black box of peer review, explaining how the process originated, how it works, and what's wrong with it. They also try brainstorming ways it could be fixed, and ask: how is the Internet changing the way we do research?

M & J discuss science communication with Howard Schneider, dean of the school of journalism at SUNY Stonybrook and former editor of Newsday. A guest at previous skeptic events, including the first annual Northeast Conference on Science and Skepticism, Schneider has argued in the past that skeptics lay too much blame at the feet of the media for public misunderstandings and misconceptions about science. Julia and Massimo question him on this point, and ask him for his thoughts on what *can* be done to improve scientific literacy. As the founder of the Center for News Literacy and the Center for Communicating Science, Schneider has plenty of thoughts to share -- including making scientists take improv classes. Should science communication involve more storytelling? And is there any way to take advantage of new, online media formats to remedy some of the weak points in the science communication process?

Is "rational spirituality" a contradiction? In this episode, Massimo and Julia try to pin down what people mean when they call themselves "spiritual," what inspires spiritual experiences and attitudes, and whether spirituality can be compatible with a naturalist view of the world. Are there benefits that skeptics and other secular people could possibly get from incorporating some variants on traditional spiritual practices -- like prayer, ritual, song, communal worship, and so on -- into their own lives? Massimo and Julia examine a variety of attempts to do so, and ask: how well have such attempts worked, and do they come with any potential pitfalls for our rationality?

n this episode Massimo and Julia ask, "Is the fundamental nature of the world knowable by science alone?", looking at the issue through the lenses of a series of related philosophical positions: determinism, reductionism, physicalism, and naturalism. All of those "isms" take a stance on the question of whether there are objectively "correct" ways to interpret scientific facts -- like physical laws, or causality -- and if so, how do we decide what the correct interpretation is? Along the way, Massimo and Julia debate the nature of emergent properties, whether math is discovered or invented, and whether it's even logically possible for "supernatural" things to exist.

In this episode, Massimo and Julia take on parapsychology, the study of phenomena such as extrasensory perception, precognition, and remote viewing. Its practitioners claim that there is more evidence for it than there is for other areas of scientific inquiry, such as string theory for which there is no empirical data at all. Yet string theory is taken seriously as a science whereas parapsychology is not. So, what is the scientific status of parapsychology? What does the best academic literature on the subject tell us? Finally, what can we learn from parapsychology about the practice of science in general?

Guest Donald Prothero joins us to discuss the common tactics and thinking of science deniers and the implications of this assault on science for our future. The denial of scientific realities in issues like global warming, creationism, vaccine safety, and AIDS, is growing in our society. Not only is our acceptance of scientific "inconvenient truths" under attack, but even scientists themselves have been threatened. Donald R. Prothero is Professor of Geology at Occidental College and Lecturer in Geobiology at the California Institute of Technology. He is the author, co-author, editor, or co-editor of 25 books, over 200 scientific papers and a number of popular books including, most recenly, "Catastrophes!: Earthquakes, Tsunamis, Tornadoes, and Other Earth-Shattering Disasters" and "Evolution: What the Fossils Say and Why It Matters". He is on the editorial board of Skeptic magazine and has been featured on several television documentaries, including episodes of Paleoworld (BBC), Prehistoric Monsters Revealed (History Channel), Entelodon and Hyaenodon (National Geographic Channel), and Walking with Prehistoric Beasts (BBC).

Guest Joseph Heath, author of “Economics Without Illusions: Debunking the Myths of Modern Capitalism,” joins us as we turn our skeptical eyes toward the treacherous dual terrain of economics and politics. We discuss the ways in which, with his book, he attempts to raise our economic literacy and empower us with new ideas. In it, he draws on everyday examples to skewer the six favorite economic fallacies of the right, followed by impaling the six favorite fallacies of the left. Heath leaves no sacred cows untipped as he breaks down complex arguments and shows how the world really works. Joseph Heath is the Director of the Centre for Ethics and Professor of Philosophy and Public Policy at the University of Toronto. In addition to his academic publications, he is the author of other popular books, among them, "The Rebel Sell : Why the Culture Can't Be Jammed" and "Efficient Society: Why Canada is as Close to Utopia as It Gets"

The media is increasingly bombarding us with reports of advances in neuroscience which claim all sorts of amazing feats, like allowing us to read our thoughts and intentions. It sounds like neurobabble. Most of these reports though are either based on bad science, reach false conclusion, or are based on conceptual misunderstanding of how our psychology works. To be fair, much of this is manufactured by the popular media but, unfortunately, some of it comes from the neuroscience community itself. So, what information can we really get from fMRIs? As with the misunderstanding of what genes are (like whether there is a God or a conservative gene), are there really parts of the brain dedicated to categories of thoughts like some of these reports claim? And, perhaps more importantly, what are the ethical implications of this neurobabble, should we arrest people who we can tell, based on this research, will be committing a crime?

Our guest Eugenie C. Scott joins us to talk about a new initiative of the National Center for Science Education (NCSE) to tackle denialism of global warming. Both evolution and global warming are “controversial issues” in the public sphere, but are not controversial in the world of science. There is some overlap between the two issues, but far more people are climate change deniers than evolution deniers. What is interesting to skeptics, however, is the similarity in the techniques that are used by both camps to promote their views. The scientific issues are presented as “not being settled,” or that there is considerable debate among scientists over the validity of claims. Evolution and global warming opponents also demonize the opposition by accusing them of fraud or other wrong-doing. Denialists in both camps practice “anomaly mongering,” in which a small detail seemingly incompatible with either evolution or global warming is considered to undermine either evolution or climate science. Although in both cases, reputable, established science is under attack for ideological reasons, the underlying ideology differs: for creationism, the ideology of course is religious; for global warming, the ideology is political and/or economic. Dr. Eugenie C. Scott is Executive Director of the National Center for Science Education, and sits on the Board of Advisors for the New York City Skeptics. She has written extensively on the evolution-creationism controversy and is past president of the American Association of Physical Anthropologists. Scott is the 2010 recipient of the National Academy of Science's Public Welfare Medal. She is the author of "Evolution vs Creationism" and co-editor, with Glenn Branch, of "Not in Our Classrooms: Why Intelligent Design Is Wrong for Our Schools."

Our guest Lou Marinoff joins us to discuss philosophical counceling, a recent trend to use philosophy as a type of talk therapy. Now, despite the provocative title of his best-selling book, “Plato, Not Prozac!: Applying Eternal Wisdom to Everyday Problems,” the idea is actually not to replace psychiatric medications with chats about the ancient Greeks. Rather, as he puts it in the introduction to the volume, you should take your medications if you really need them, but once your brain is back to a normal functionality you will likely still be faced with the same existential problems that plague most human beings. And that’s where philosophy might help. Lou Marinoff is the Chair of the Department of Philosophy at The City College of New York and a founder of the American Philosophical Practitioners Association. His other books include "The Middle Way: Finding Happiness in a World of Extremes" and "Therapy for the Sane."

Is the search for extraterrestrial intelligence, or SETI, solid science, pseudoscience, or something else, as Massimo argues in his book "Nonsense on Stilts"? What are the theoretical foundations and empirical evidence that justify a multi-decade research program, and what are its chances of succeeding? Have we learned anything thanks to SETI? Also, if the universe is infinite, what problems does this pose for utilitarian ethics?

All of us who are involved in the skeptics movement are regularly confronted with one of two reactions when revealing ourselves as skeptics: either that we are cynics, or that, like the classic skeptics, we don't believe that anything is knowable. In this episode, Massimo and Julia take us trough the history of skepticism. From its roots in ancient Greece, to Descartes, the last rationalist, to David Hume, the father of modern skepticism, and to today's modern skeptic movement. Also, is anything really knowable? How do we know that we really exist and are not residents of a cosmic holodeck?

Our guest Rebecca Newberger Goldstein joins us to talk about Baruch Spinoza and Kurt Gödel, the subjects of her books "The Proof and Paradox of Kurt Gödel" and "Betraying Spinoza: The Renegade Jew who Gave Us Modernity." The topics include the idea of "Spinoza's God" and his concept of a theory of everything, their views on the limits of reason and objective reality, Gödel's theorems and its repercussions in philosophy and mathematics, and his legendary friendship with Albert Einstein. She also talks about her novels and her experience of being both a novelist and a writer of non-fiction works. Rebecca Newberger Goldstein grew up in White Plains, New York, graduated summa cum laude from Barnard College and immediately went on to graduate work at Princeton University where she received her Ph.D. in philosophy. In 2008, she was designated a Humanist Laureate by the International Academy of Humanism, and was awarded an Honorary Doctorate by Emerson College. Currently she is a Research Associate in the Department of Psychology, Harvard University. She is the recipient of numerous awards, including the coveted MacArthur “Genius Award.” She was named Humanist of the Year 2011 by the American Humanist Association, and she was given the "Freethought Heroine Award" by the Freedom From Religion Foundation in 2011. In addition to her non-fiction works, she is the author of a number of novels, including "The Late-Summer Passion of a Woman of Mind; The Dark Sister." Her latest work is "Thirty-Six Arguments for the Existence of God."

In this episode we tackle the curious case of pseudoscience or mysticism that works, or seems to, at least some of the times. From acupuncture to chiropractic, from yoga to meditation, what do we make of instances where something seems to have the desired effect for the wrong reasons (e.g., acupuncture), or might otherwise be a perfectly acceptable technique which happens to come intricately bundled with mysticism (e.g., yoga)?

No, this episode is not about "elevatorgate" or the Watson-Dawkins debacle, but we do use these recent (in)famous events as a springboard for a broader discussion of women in skepticism and science. Is there a misogyny problem in the skeptic and atheist communities? Why aren't there more more women involved in these communities? Also, Julia tells us about her own experience as a young woman skeptic.

Following up on their interview with Robert Zaretsky on the dispute between David Hume and Jean-Jacques Rousseau about the limits of reason, Julia and Massimo expand the topic to include a discussion of the failure of “foundational” projects (e.g., the quest for the ultimate bases of scientific reasoning, or of logic and mathematics). Also, our take on a recent paper on the evolutionary psychology of reasoning that has made mainstream news.

Imagine a time when a dispute between two philosophers was the talk of high society. That is the time that our guest, Robert Zarertsky, describes in his book "The Philosophers' Quarrel: Rousseau, Hume, and the Limits of Human Understanding." He tells the story of the short and dramatic friendship between Hume and Rousseau. Hume, who championed the progress of the sciences and arts, and Rousseau, who questioned progress, wondering whether it was just another word for moral decay and despair. He also discusses the implications their friendship may have had on the Enlightenment's conceptions of reason and human understanding. Robert Zaretsky is a professor of French history at the University of Houston Honors College and the Department of History. He has published several books about philosophy and history of philosophy.

Massimo and Julia answer listeners' questions. In this installment the topics include: what would they teach in a class in critical thinking, their view of analytics vs. continental philosophy, the ethics of profiteering from a drought in examplistan, how do they compartmentalize their rationality, how does modern technology affect the way we think about things, and what is or should be the primary purpose of our species. Also, is there really a rational argument to prove the divine origin of the bible?

In this episode we tackle the never ending debate about free will, which David Hume famously defined as “a power of acting or of not acting, according to the determination of the will.” We do this with a couple of twists. We begin by examining the concept of free will from the standard philosophical perspective, then ask what — if anything — modern neuroscience can tell us about it, and come back to the interface between philosophy and science to explore how the two approaches may complement each other.

Our guest Holden Karnofsky joins us to discuss Givewell, the nonprofit organization he founded. Givewell is devoted to investigating charities and NGOs to determine how much of an impact they’re having. You could call it “evidence-based philanthropy.” He discusses how Givewell evaluates charities, and what the research has to say about various controversies as well as the conventional wisdom in the nonprofit world: Can large charities be efficient? Is the percentage of the donation that goes to expenses really a useful metric? Should we focus on problems closer to home instead of giving to foreign countries? Do microfinance NGOs like Kiva or Grameen Bank live up to their claims? And should or can charities be evaluated objectively?

Debates over what’s important to happiness — Money? Children? Love? Achievement? — are ancient and universal, but attempts to study the subject empirically are much newer. What have psychologists learned about which factors have a strong effect on people’s happiness and which don’t? Are parents really less happy than non-parents, and do people return to their happiness “set point” even after extreme events like winning the lottery or becoming paralyzed? We also tackle some of the philosophical questions regarding happiness, such as whether some kinds of happiness are “better” than others, and whether people can be mistaken about their own happiness. But, perhaps the hardest question is: can happiness really be measured?

Universities all around the country are closing programs in the humanities, at least in part because of the increasing widespread attitude that higher education should be treated as a business, and that programs that bring in money in the form of high tuitions from students and external grants are to be prioritized. SUNY Albany, for example, announced in the Fall of 2010 that the departments of French, Italian, Classics, Russian and Theater Arts were being eliminated. So, what is the point of studying languages, literature, history or philosophy? Can we, and perhaps more importantly, should we quantify their value? Can we have universities that focus only on science and marketable skills?

In this episode we explore philosophy of science: What is it about, and should it matter to scientists? Massimo and Julia also discuss some of the most important questions in philosophy of science now, and some historical debates between leading philosophers of science, like Thomas Kuhn and Karl Popper, over how science should or does work. So is philosophy of science, as Richard Feynman famously quipped, "as useful to scientists as ornithology is to birds?" Or was philosopher Daniel Dennett closer to the truth when he said, "There is no such thing as philosophy-free science, only science whose philosophical baggage is taken on-board unexamined?"

If the recent hoopla about the royal wedding wasn’t enough to remind you, we live in a culture of celebrity, one where famous people command our attention and often pontificate on things they know nothing about. Obvious examples include the nonsense spewed out by Prince Charles about alternative medicine, and the former model Jenny McCarthy and her dangerous notion that vaccines are harmful because they cause autism. But these, of course, are easy targets. What are we to make of Ray Kurzweil (he of Singularity fame), who recently co-authored a book with a homeopath? Or of otherwise savvy political commentator Bill Maher, who doesn’t trust vaccines or anything coming from “Western” medicine? And then there are highly respectable intellectuals, like Stephen Hawking, who write off entire fields of inquiry (philosophy, in his case), without apparently knowing much about them. So what is going on here? Why do so many people listen to Jenny McCarthy? And why do so many bright minds go public with ridiculous notions? Is there a pattern? Can we do something to defend ourselves and the public from the celebrity attack on reason?

In this one hour episode, recorded live at the 2011 Northeast Conference on Science and Skepticism, Massimo and Julia discuss bioethics with two special guests: Jacob Appel, doctor, author, lawyer and bioethicist; and Jennifer Michael Hecht, poet and historian of science. Topics covered included: Should parents be allowed to select the gender and sexual orientation of their babies? Should pharmacists and physicians be allowed to refuse to provide treatments that violate their own religious or ethical principles? And when is assisted suicide acceptable?

We all think that science is about objectivity and “just the facts, ma’am.” Not so fast, philosophers, historians and sociologists of science have been arguing now for a number of decades. To begin with, there are values embedded in the practice of science itself: testability, accuracy, generality, simplicity, and the like. Then there are the many moral dimensions of science practice, both in terms of ethical issues internal to science (fraud) and of the much broader ones affecting society at large (societal consequences of research and technological advances). Then there is the issue of diversity, where until very recently, and in many fields still today, science has largely been an affair conducted by white males. Finally, the issue of which scientific questions we should pursue and, often, fund with public money. And to complicate things further, should scientists consider the societal consequences of their research before deciding to publish?

Vegetarianism is a complex set of beliefs and practices, spanning from the extreme “fruitarianism,” where people only eat fruits and other plant parts that can be gathered without “harming” the plant, to various forms of “flexitaranism,” like pollotarianism (poultry is okay to eat) and pescetarianism (fish okay). So, what does science have to say about this? What is the ethical case for vegetarianism? And, is it true that vegetarians are more intelligent than omnivores? Not unexpectedly, the answers are complex, so the debate will rage on.

Cordelia Fine joins us from Melbourne, Australia to discuss her book: "Delusions of Gender: The Real Science Behind Sex Differences." Sex discrimination is supposedly a distant memory, yet popular books, magazines and even scientific articles increasingly defend inequalities by citing immutable biological differences between the male and female brain. That’s the reason, we’re told, that there are so few women in science and engineering and so few men in the laundry room — different brains are just better suited to different things. Drawing on the latest research in developmental psychology, neuroscience, and social psychology, Fine sets out to rebut these claims, showing how old myths, dressed up in new scientific finery, are helping to perpetuate the sexist status quo. Cordelia Fine studied Experimental Psychology at Oxford University, followed by an M.Phil in Criminology at Cambridge University. She was awarded a Ph.D in Psychology from University College London. She is currently a Senior Research Associate at the Centre for Agency, Values & Ethics at Macquarie University, and an Honorary Research Fellow at the Department of Psychological Sciences at the University of Melbourne. Her previous book is "A Mind of Its Own: How Your Brain Distorts and Deceives."

In a continuation of episode 28, Massimo and Julia sit down for a Q&A session in front of a live audience at the Jefferson Market Library in New York City. The audience's questions include whether economics and evolutionary psychology are really science, what's the deal with the placebo effect, the influence of corporate money on scientific research, and how can some scientists publish legitimate research and still believe in pseudo-science. Also, vegetarianism: is it about science, ethics, or both?

Massimo and Julia sit down in front of a live audience at the Jefferson Market Library in New York City for a conversation about science, non-science, and pseudo-science. Based on Massimo's book: "Nonsense on Stilts: How to Tell Science from Bunk" the topics they cover include whether the qualitative sciences are less reliable than quantitative ones, the re-running of the tape of life, and who is smarter: physicists, biologists, or psychologists? Also, why are evolutionary psychologist so fixated on sex? The live Q&A follows in episode 29

In honor of our first anniversary we invited Historian Timothy Alborn to help us understand the arbitrary nature of anniversaries, both those that mark events of personal significance and those that have a wider societal impact. We chose to record this episode on a very special "holiday": Perihelinox. If you've never heard of it it's because it was recently made up by our producer, Benny Pollak, to celebrate the night of the year when the earth is closest to the sun. Nothing is sacred in this episode, from Christmas to Kwanza, to Hanukkah, to Royal Jubilees. And, the Sex Pistols? Timothy Alborn is a historian and the Dean of Arts and Humanities at the City University of New York—Lehman College (and, incidentally, Massimo's boss). He has a Ph.D. in History of Science from Harvard University. His recent publications include "Regulated Lives: Life Assurance and British Society, 1840-1920" and "Conceiving Companies: Joint-Stock Politics in Victorian England."

In a recent article in the New York Times, Nicholas Wade reported that the American Anthropological Association had decided “to strip the word ‘science’ from a statement of its long-range plan.” Is this just a reflection of the long standing division between physical and cultural anthropology or is there more here? The revised statement says that “the purposes of the association shall be to advance public understanding of humankind in all its aspects,” a wording that opens the possibility for cultural anthropologists to engage in public advocacy on behalf of cultures they are studying. So, what kind of discipline is anthropology, after all? And, more broadly, should scientists cross the line from research into public advocacy?

Massimo and Julia answer listeners' questions, as they try to stay away from politics. In this installment the topics include: is quantitative research more scientific than qualitative one, can philosophers really claim to have expertise on something, is skepticism just another name for intelligence, what about feminist philosophy, bayesian reasoning, and what are M&J's anti-akracia strategies?

The term meme was introduced by Richard Dawkins in his 1976 bestseller "The Selfish Gene."Dawkins was trying to establish the idea that Darwinian evolution is a universal, almost logically necessary phenomenon. He couldn't, however, point to exobiological examples to reinforce the concept of universal Darwinism, so he turned to cultural evolution, renamed “ideas” as “memes” (in direct analogy with genes), and voilà, the field of memetics was born. Despite staunch support by authors such as Susan Blackmore and Daniel Dennett, among others though, serious questions can be raised about memes and memetics as a viable concept and field of inquiry. To begin with, how is this different from classical studies of gene-culture co-evolution? Second, what, exactly are memes, i.e. what is their ontological status? Third, how do memes compete with each other, and for what resources? Is it even possible to build a functional ecology of memes, without which the statement that the most fit memes are those that spread becomes an empty tautology? Could this explain why the "Journal of Memetics" closed shop, or is it that they discovered everything there was to discover about memes?

Our guest, Carol Tavris discusses her book (co-authored with Elliot Aronson) "Mistakes Were Made (But Not by Me): Why We Justify Foolish Beliefs, Bad Decisions, and Hurtful Acts." In it they describe how our powerful cognitive dissonance engine of self-justification gives us the incredible ability to rationalize events and beliefs so that we always end up being better than average at being right. Also, how we are forced into these rationalizations by our absolute need to somehow square our most dearly held opinions of ourselves with the nasty tendency of some facts to contradict them. Carol Tavris is a social psychologist who has tought at UCLA. She has written for many publications, including the NY Times and the LA Times. She is the author of a number of books, including "The Mismeasure of Women" and the recently re-released, "Psychobabble and Biobunk."

Our Guest, Dr. Steven Novella discusses a recent article in The Atlantic in which researcher John Ioannidis shows that 40% of papers published in top medical journals are either wrong or make exaggerated claims (and those are the top journals!). He also discusses the difference between Science and Evidence based medicine. Also, Zombies: are they epidemiologically possible? Steven Novella is an academic clinical neurologist at the Yale University School of Medicine. He is the host of the Skeptics Guide to the Universe podcast, author of the Neurologica blog, and co-editor of the Science Based Medicine blog.

Our guest, Joshua Knobe, is a philosopher interested in cognitive science, so interested, in fact, that he has contributed to establishing a whole new branch of inquiry known as experimental philosophy — and he plausibly claims that the name is not actually an oxymoron! The idea is summarized in this way on one of the major web sites devoted to the enterprise: "Experimental philosophy, called x-phi for short, is a new philosophical movement that supplements the traditional tools of analytic philosophy with the scientific methods of cognitive science. So experimental philosophers actually go out and run systematic experiments aimed at understanding how people ordinarily think about the issues at the foundation of the philosophical discussion.” Joshua Knobe is an assistant professor at Yale University, affiliated both with the Program in Cognitive Science and the Department of Philosophy . Most of his work involves using the kinds of experimental methods associated with cognitive science to address the kinds of questions associated with philosophy.

Massimo and Julia answer listeners' questions. In this installment the topics include: can political discourse be rational, who changed M&J's opinion on something and when have they changed someone's opinion, how do they guard against biases when they debate people, the morality of bestiality, and did Samir Okasha really solve the induction problem? Plus, M&J's favorite sources for philosophy: - Internet Encyclopedia of Philosophy - Stanford Encyclopedia of Philosophy - philpapers.org - An Enquiry concerning Human Understanding by David Hume - Language, Truth, and Logic by Alfred Jules Ayer - Mortal Questions byThomas Nagel - Practical Ethics by Peter Singer

Ever notice how some beliefs only seem to become stronger, even as they're repeatedly debunked? For example, the belief that Barack Obama is a Muslim, or that Bush banned all stem cell research in the country. Brendan Nyhan tells about what he's learned from his research studies and his experience maintaining Spinsanity, a watchdog blog monitoring political misinformation. Is there any hope of clearing up false beliefs if denials simply make the problem worse? Brendan does offer hope, but it won't be easy. Brendan Nyhan is a a Robert Wood Johnson Scholar in Health Policy Research at the University of Michigan. He received a Ph.D. from the Department of Political Science at Duke University in May 2009. In 2011, He will join the Department of Government at Dartmouth College as an assistant professor. His research focuses on political scandal and misperceptions. He also conducts research on social networks and applied statistical methods.

You’ve heard the claims: men are inclined to cheat on women because natural selection favors multiple offspring from multiple mates, especially if you don’t have to pay child support. Even rape has been suggested to be the result of natural selection in favor of “secondary mating strategies” when the primary ones fail. Welcome to evolutionary psychology, a discipline curiously situated at the interface between evolutionary science and pop psychology, where both wild and reasonable claims seem to clash against the wall of an incredible scarcity of pertinent data. The issue is not whether it makes sense to apply evolutionary principles to the study of human behavior. Of course it does, human beings are no exception to evolution. But the devil is in the details, and the details deal with the complexities and nuances of how exactly evolutionary biologists test adaptive hypotheses, as well as with the nature of historical science itself.

What's so great about being human, anyway? The transhumanist movement -- epitomized by organizations like Humanity+ and blogs like Accelerating Future -- advocate the pursuit of technologies to fundamentally change the human condition, tinkering with our brain, bodies and genomes to make ourselves smarter, stronger, happier, and longer-lived. But many people worry that tampering with human nature could have dire consequences for individuals and society alike. In Our Posthuman Future, political theorist Francis Fukuyama sums up the position of the bioconservatives when he warns that new technologies may "in some way cause us to lose our humanity -- that is, some essential quality that has always underpinned our sense of who we are and where we are going," he writes. In this episode of Rationally Speaking, Massimo and Julia ask, first, are the goals of transhumanism realistic, and second, are they desirable?

At a talk he gave at TAM 8, Massimo argued that non-experts in a field aren't qualified to reject an expert consensus, such as that on anthropogenic climate change. Most recently, he has taken Jerry Coyne to task for making a philosophical argument without having the necessary expertise. This raises a number of questions: Are there fields that have no experts, or that have pretend experts? If there is a lot of disagreement among experts on a topic, should we take any individual expert's opinion less seriously? How much consensus is required before a non-expert should say, "OK, looks like this question really is settled"? Perhaps noted expert George Carlin had it right when he said: "I have as much authority as the pope, I just don't have as many people who believe it."

In the first of what we hope will be a regular feature of Rationally speaking, Massimo and Julia answer listeners' questions. These range from what are M & J's sacred cows, to how we should approach morally repugnant claims made by venerated philosophers, to whether we are deluding ourselves believing that our votes count.

Author, science historian, philosopher, and poet Jennifer Michael Hecht discusses her views on science, religion, and skepticism. She talks about her book "The Happiness Myth", showing how the very concept of happiness has changed dramatically both in time and across cultures, to the point that it may make little sense to simply ask “are you happy”? Also she makes her skeptical comments on the findings of science, for instance concerning eating and exercise habits, and how the skeptic community's reliance on science borders on religion. Jennifer teaches at the New School in New York City. She is the author of Doubt: A History: The Great Doubters and Their Legacy of Innovation from Socrates and Jesus to Thomas Jefferson and Emily Dickinson and of The Happiness Myth: The Historical Antidote to What Isn't Working Today, among other books.

Is it possible that superstition is actually good for you? Well, it turns out that superstition may, at least some of the time, have beneficial effects. A paper published in 2008 in Science for example, suggests that lacking control over a situation increases people’s propensity to see illusory patterns — the implication being that the latter (a typical component of superstition) ameliorates stress when we feel that things are out of hand. Also, a recent study published in Psychological Science shows that superstition improves people’s performance on certain tasks, presumably by making them more self-confident than they would be otherwise. Add to this a recent article in Scientific American to the effect that people with Asperger’s syndrome are less likely to project agency onto life’s events (and hence tend to be less superstitious), and suddenly the skeptic might not feel so cocky about being skeptical. Of course we're not advocating in favor of superstition on the sole ground that it may be psychologically helpful. Still, what happens when something that we devote so much time fighting against turns out not to be entirely bad after all?

Philosophers are often accused of engaging in armchair speculation, as far removed from reality as possible. The quintessential example of this practice is the thought experiment, which many scientists sneer at precisely because it doesn’t require one to get one’s hands dirty. And yet scientists have often engaged in thought experiments, some of which have marked major advances in our understanding of the world. Just consider the famous example of Galileo’s thought experiment demonstrating (rather counter intuitively) that two objects of different weight must fall at the same speed. And, perhaps more famously, Einstein's light thought experiments, which lead him to the formulation of the theory of relativity. And then, there are the other kind, like philosopher David Chalmers' famous thought experiment about zombies and the so-called "hard problem" of consciousness. Chalmers comes up with an (admittedly ingenious) little story, and we are supposed to deduce from it the momentous conclusion that there is more than matter/energy to the universe? Still, there are plenty of good thought experiments in philosophy, beginning with the so-called trolley dilemmas meant to probe our moral intuitions.

Our special guest this episode is Eugenie Scott, executive director of the National Center for Science Education, the premiere organization fighting for sound scientific educational standards in this country, and a permanent thorn in the ass of creationists and IDers nationwide. Genie updates us on the status of the ID and creationist wars, as well as other issues related to the intrusion of religion in science education. We also recount how, in what may be a very rare event, Genie made Massimo change his mind about something! Genie is a physical anthropologist by training, and enjoyed an academic career at the University of Kentucky, University of Colorado and California State, before devoting her efforts full time to a constant front-line fight against irrationalism. For this she has been rewarded not just with six honorary degrees (at last count), but also with the first Stephen Jay Gould prize from the Society for the Study of Evolution, and most recently with the prestigious National Academy of Science Public Welfare Medal. She has also authored the excellent Evolution vs Creationism and co-edited (with Glenn Branch) Not in Our Classrooms: Why Intelligent Design Is Wrong for Our Schools.

The focus of this episode is Massimo's new book, Nonsense on Stilts: How to Tell Science from Bunk. The book, broadly speaking, is about what philosopher Karl Popper famously called the demarcation problem: how do we tell the difference among science, non-science and pseudoscience? We explore the complex relationship among these, ranging from solid science like fundamental physics and evolutionary biology to definite pseudosciences like astrology and creationism. In the middle are the more interesting borderline areas that include the search for extraterrestrial intelligence, evolutionary psychology, and even superstring theory, to name but a few. We also discuss other topics covered in the book, including the whole issue of expertise and Think Tanks, which plays such an important role especially in media presentations of issues such as evolution, climate change, HIV-AIDS, or the alleged connection between vaccines and autism. Julia and Massimo also address the ultimate question about pseudoscience: why do we care?

It’s very easy to make fun of not-so-educated people who reject evolution, but what happens when one of the most prominent contemporary philosophers, Jerry Fodor, writes a book about “What Darwin Got Wrong”? Similarly, we can dismiss extreme right wing politician like Senator Jim Inhofe of Oklahoma, who thinks global warming is a worldwide conspiracy of crazy scientists bent on destroying the American way of life. But what happens when two icons of the skeptic movement, Penn & Teller, do a whole show in which they completely deny all the well established evidence of anthropogenic climate change. And of course it is easy to laugh at Jenny McCarthy, the kook who claims (with Oprah Winfrey’s support) that she “just knows” that vaccines cause autism. But, what happens when a politically savvy atheist like Bill Maher says that people who get flu shots are “idiots?"

The Anthropic Principle (AP), in its many forms, attempts to explain why our observations of the physical universe are compatible with the life observed in it. From the Weak AP (WAP), which in one form states that "conditions that are observed in the universe must allow the observer to exist", to the Strong AP (SAP) which in one version states that: “The Universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage,” they all try to answer the question of why there is life in the universe, or why the fundamental constants are the way they are. But, do any of these principles add anything to our understanding of the ultimate question of life and the universe? Perhaps the best answer is embedded in Martin Gardner’s sarcastic proposal of the Completely Ridiculous Anthropic Principle (CRAP): “At the instant the Omega Point is reached, life will have gained control of all matter and forces not only in a single universe, but in all universes whose existence is logically possible; life will have spread into all spatial regions in all universes which could logically exist, and will have stored an infinite amount of information, including all bits of knowledge which it is logically possible to know. And this is the end.”

We are taking on fundamental physics! Our guest, Peter Woit, is a physicist in the Department of Mathematics at Columbia University and author of "Not Even Wrong: The Failure of String Theory and the Search for Unity in Physical Law." We discuss the apparently peculiar state of theoretical physics and the rather startling possibility that superstring theory — the best candidate in decades as the elusive “theory of everything” — may actually have been a colossal dead end for the physics community. We also explore the meaning of theory in science, and what is the connection between theory, observation and experiment. As it turns out, superstring theory has not been able to make any empirically testable predictions, which supports the argument that perhaps it isn’t — as Peter puts it — “even wrong,” meaning that it just isn’t science.

Fluffy Thinking is a peculiar type of uncritical thinking that sounds sophisticated, and is next to impossible to criticize frontally both because it barely has anything to do with empirical evidence, and because it is hard to articulate what, exactly, these people are saying. These people include scientific luminaries like Freeman Dyson and Paul Davies. Also, Karen Armstrong, author of "The Case for God", and Krista Tippett, author of "Einstein's God" and host of National Public Radio's "Speaking of Faith", where scientific notions are regularly distorted and mixed up with barely intelligible mystical “insights” that are put forward as profound truths. The question is not only whether there is anything interesting in what these people are saying, but rather the much more difficult issue of why it is that smart individuals, who make their living thinking and writing about science and philosophy, are attracted by fluffy thinking.

Dr. Neil deGrasse Tyson joins Massimo and Julia to discuss the need for a space program. Many scientists (and most people in the skeptic community) simply assume that funding outlets like NASA are a good idea. But, can scientists justify the enormous expense involved, not just in terms of their personal curiosity, but as a matter of tangible and intangible benefits to society at large? Should we go back to the Moon and establish a permanent base? Is it worth the expense and likely risk to human life to attempt a mission to Mars? What is a space station for, anyway? Dr. Tyson is an astrophysicist by training and director of the Hayden Planetarium at the American Museum of Natural History in Manhattan. He is also the host of PBS's science NOW. His latest book is “The Pluto Files: The Rise and Fall of America's Favorite Planet.”

"Accommodationist" is a word that began to appear in recent months during public debates over science and religion. The derogatory term has been applied to atheists and rationalists like Eugenie Scott, at the National Center for Science Education, and Chris Mooney, science writer at Discover Magazine, who maintain that science and faith are not necessarily incompatible. Although the debate is frequently framed as a practical one, about what the tactics of the secular movement should be, it is also a philosophical one, hinging on the question of the epistemic limits of science. In this episode, we examine the arguments being made by and against the so-called "accommodationists," and ask: Can science disprove religious and supernatural claims?

Our guest, Prof. Peter Turchin from the University of Connecticut, joins Massimo and Julia to discuss whether history can be studied and understood in a scientific manner. In an article in Nature (3 July 2008) on what he termed “cliodynamics,” he discusses the possibility of turning history into a science. In it, he proposes that history, contrary to what most historians might think -- is not just one damn thing after another, that there are regular and predictable patterns, from which we can learn and that we can predict. Of course, he is not the only scientist to have turned to history in an attempt to make that field more scientific, Jared Diamond’s Guns, Germs, and Steel and Collapse immediately come to mind. And naturally, many historians vehemently object to what they perceive as a crude scientistic attempt at interdisciplinary colonization.

Will science ever really be able to explain love? Science has already found correlations between particular hormones and certain forms or stages of love. However, no matter how many correlations we find between brain activity and love, correlation does not imply causation. And what does it mean to explain love scientifically -- would that change our attitude towards it? We realize that raising this subject risks fueling the widespread and irritating misconception that “skeptic” = “cynical killjoy,” which is the last thing we want to do. As good skeptics though, what do we do when faced with a mysterious and unexplained phenomenon? We look for explanations!

Why is "speaking rationally" a worthwhile goal anyway? It’s not self-evident, at least not to many people. Human beings certainly don’t seem made for it. Aristotle may have famously dubbed us "the rational animal," but cognitive science tells a different story, with plenty of evidence that our brains blithely flout logic all the time and are excellent at rationalizing our irrational decisions after the fact. Indeed, it is reasonable to ask why fight our irrational natures to begin with? After all, some argue that irrationality can make us happier, at least in certain situations. Then again, perhaps there is a problem with the whole idea of arguing for irrationality...