Through the conversation.
17 sections010:00 – 2:59Introduction to Hugo Mercier and the Evolutionary Psychology of Reasoning
Hosts Dave Pietraszewski and David Pinsoff introduce the podcast episode and guest Hugo Mercier, a researcher at the Institut Jean Nicod in France associated with the Paris School of Cultural Evolution. They discuss his books, 'The Enigma of Reason' and 'Not Born Yesterday,' highlighting topics such as reasoning, epistemic vigilance, and why humans hold specific beliefs without being overly gullible.
The hosts introduce Hugo Mercier and his work on reasoning and epistemic vigilance.
“the person we're going to talk to today is Hugo Mercier” 0:46
They mention his books on the evolutionary psychology of reasoning and gullibility.
“The Enigma of Reason is his first book about the evolutionary psychology of reasoning” 1:46
023:00 – 12:04The Argumentative Theory of Reasoning and Confirmation Bias
Hugo Mercier explains the argumentative theory of reasoning, arguing that the evolutionary function of human reason is not solitary logical calculation, but rather communicating with others by exchanging arguments and justifications. Mercier and the hosts discuss how this framework accounts for well-documented phenomena like confirmation bias or myside bias, drawing parallels to evolutionary functions like reproduction where individuals lack conscious awareness of ultimate biological purposes.
Hugo Mercier explains that the evolutionary function of human reasoning is not solitary thought, but reasoning with others through arguments and justifications.
“we don't think that's what reasoning is for. So in in evolutionary terms, uh we've suggested that the function of of reason” 3:57
Mercier notes that people spontaneously find overwhelmingly arguments supporting their own view, known as confirmation bias or myside bias.
“people have a confirmation bias or my side bias. So whenever you're you're reasoning about anything” 10:01
Dave Pietraszewski, David Pinsof, and Hugo Mercier discuss confirmation bias, also known as my-side bias, and how the argumentative theory of reasoning explains why people readily produce supporting arguments for their existing views while struggling to see opposing perspectives.
whatever original intuition or feeling you have, you only find reasons supporting that, you will never change your mind
“If whatever original intuition or feeling you have, you only find reasons supporting that, you will never change your mind.” 12:53
0413:52 – 24:06Confabulation, Social Vigilance, and Cooperative Bullshitting
The speakers examine confabulation and why people accept justifications for behavior despite potential biases. They explore epistemic vigilance, reputational costs, and instances of cooperative bullshitting in cultural and political groups, such as attributing misfortunes to supernatural causes.
most of the justifications we give are actually decent justifications
“most of the justifications we give are actually decent justifications.” 16:33
when everyone has the same biases or the same interests to come up with a particular justification
“in some cases when everyone has the same biases or the same interests to come up with a particular justification.” 22:02
0524:06 – 31:12Witchcraft Accusations and the Evolutionary Roots of Bias
Dave Pietraszewski, David Pinsof, and guest Hugo Mercier discuss how social blame, such as witchcraft accusations in small-scale societies, helps individuals avoid costly helping obligations while deflecting personal responsibility. They explore whether human inability to detect our own biases functions as a design feature to prevent undermining the persuasiveness of our arguments, and touch upon confirmation bias and depression.
The guest explains that people use witchcraft accusations to avoid helping neighbors in misfortune while deflecting personal blame.
“So no one really has to help because they brought it on themselves.” 24:31
Mercier argues that human inability to detect one's own biases does not require special evolutionary pressure beyond the baseline complexity of cognition.
“You just not you just there's no pressure for that mechanism you're describing to evolve.” 27:46
0631:12 – 36:08Functions of Reasoning and Coordinating Confabulations
Hugo Mercier outlines the two main functions of reasoning: exchanging arguments to change minds and justifying oneself. The speakers discuss how political, cultural, and conversational opinions often serve reputation-building and coordination of justifications rather than pure truth-seeking, with individuals anticipating social disagreement and tailoring explanations to fit their audience.
Mercier outlines two primary functions of reasoning: exchanging arguments to alter conclusions and justifying oneself.
“so when we talk about reasoning, for us there are two main functions.” 31:18
Pinsof suggests that conversation often functions as coordinating confabulations or justifications for underlying personal views.
“what I'm hearing from you is that a lot of conversation and reasoning is about coordinating confabulation.” 33:15
0736:08 – 45:53Verbal Narratives, Confabulation, and Plausible Justifications
Dave Pietraszewski, David Pinsof, and Hugo Mercier discuss the disconnect between underlying behavioral drivers and verbal confabulations. They examine how people utilize vague, unfalsifiable, or socially convenient justifications to support their actions, and how these narratives persist when they lack rigorous critical pushback from outsiders.
the real reasons why we're doing things and then the verbal narratives are sort of really two different independent streams almost.
“the real reasons why we're doing things and then the verbal narratives are sort of really two different independent streams almost” 37:02
if you give a confabulation that's more plausible and defensible, that that might work.
“If I give a confabulation that's more plausible and defensible, that that might work.” 41:27
0845:53 – 48:09Conversational Lazy Arguments and the Need for Disagreement
Hugo Mercier and the hosts explore how conversational settings encourage lazy initial arguments because people do not need strong justifications unless they face direct disagreement. They discuss how institutionalized debate and peer pushback—such as in science and clinical trials—are essential for sharpening arguments and improving epistemic quality.
in a dialogic setting, it makes a lot of sense to be quite lazy about the the justifications we or the the arguments we produce.
“in a dialogic setting, it makes a lot of sense to be quite lazy about the the justifications we or the the arguments we produce.” 46:47
you absolutely need disagreement to sharpen your arguments. That's how the quality of arguments increases.
“you absolutely need disagreement to sharpen your arguments. That's how the quality of arguments increases.” 47:37
Dave Pietraszewski, David Pinsof, and guest Hugo Mercier discuss the evolutionary and cognitive nature of reasoning, distinguishing general inference from a specialized mechanism dedicated to finding and evaluating reasons through social feedback and structured learning.
The reality we believe or we suggest is that you have many, many, you know, inference inferential mechanisms.
“The reality we believe or we suggest is that you have many, many, you know, inference inferential mechanisms.” 49:35
And one of these mechanisms, uh, its task happens to be finding and evaluating reasons.
“And one of these mechanisms, uh, its task happens to be finding and evaluating reasons.” 49:46
David Pinsof pushes back with a solitary counterexample involving chess strategy, leading Hugo Mercier to clarify that individual strategic planning relies on different cognitive mechanisms than social reasoning, which specifically requires exchanging reasons with others.
the cognitive mechanisms that you're using to to anticipate what you would what your opponent would do at chess or or to take these kind of strategic decisions are just different from the mechanisms that allow us to to find and evaluate reasons.
“the cognitive mechanisms that you're using to to anticipate what you would what your opponent would do at chess” 58:00
Host David Pinsof asks guest Hugo Mercier how his work on epistemic vigilance and people not being gullible reconciles with confabulation and the acceptance of questionable beliefs. Mercier explains that humans possess cognitive mechanisms to evaluate communicated information because incentives do not always align. People remain critical when they disagree, but relax their criteria and accept justifications more easily when they already agree with the conclusion.
Individuals are much more critical of arguments when they disagree, whereas they relax their evaluative criteria when they already accept a given conclusion.
“when you do disagree, then you'll be much more critical” 1:04:45
Host David Pinsof highlights the distinction between intuitive beliefs—which directly guide behavior and are connected to the nervous system—and reflective beliefs, which are functionally inert and serve social functions. Mercier illustrates this difference by contrasting individuals who witness real conspiracies with conspiracy theorists, noting that true witnesses experience genuine fear and caution, whereas theorists display muted emotional reactions while remaining unusually vocal.
Intuitive beliefs directly guide human behavior in concrete ways and connect closely to the nervous system.
“intuitive beliefs are the ones that are often they actually guide our behavior” 1:07:59
People who endorse certain high-stakes conspiracy theories often lack the genuine fear and cautious behavior characteristic of those who have witnessed real conspiracies.
“if the CIA was powerful enough to pull off 9-11, they could kill you quite easily” 1:10:33
Hugo Mercier and David Pinsof discuss how reflective beliefs can function as social signals rather than genuine intuitive convictions. Pinsof suggests that common inferences drawn from actions create social incentives for signaling, comparing certain beliefs to pseudoscience. Mercier responds that while signaling explains widespread cultural spread, initial beliefs still must meet a minimum threshold of plausibility and epistemic vigilance.
What's tricky with reflective beliefs is that on the one hand, they are held in that little box in which we usually keep things that we think are false.
“What's tricky with reflective beliefs is that on the one hand, they are held in that little” 1:12:37
So if you believe in the Holy Trinity, you're a loyal member of the group. As soon as we all make that inference, it creates an incentive for everyone to try to conspicuously signal that they believe in the Holy Trinity.
“if you believe in the Holy Trinity, you're a loyal member of the group.” 1:15:28
The speakers examine how beliefs become widespread initially, discussing the role of group polarization, outgroup hostility, and intentional manipulation through advertising and propaganda. Mercier explains that persuasive messages and advertisements ultimately succeed by tapping into pre-existing human desires and evolutionary preferences, such as the natural appeal of sugar.
The reason why it might exist in the first place is because there's an abortion debate and people are kind of trying to come up with justifications for their side of the issue.
“the reason why it might exist in the first place is because there's an abortion debate” 1:20:29
On the whole, these things work because they tap into things that people want to do in the first place.
“on the whole, these things work because they tap into things that people want to do” 1:23:11
Dave Pietraszewski, David Pinsof, and guest Hugo Mercier discuss the effectiveness of health messages, advertising, and consumer choices regarding food items like vegetables, sugar, and ice cream. They debate whether dietary choices stem from intrinsic preferences or structural market influences, highlighting the role of product availability and choice architecture.
If you give your child ice cream, you don't need advertising. They're gonna like most most children are gonna like ice cream.
“If you give your child ice cream, you don't need advertising.” 1:28:23
The choice between ice cream and broccoli, that's not gonna be the ad, that's just because the ice creams are better.
“Whereas the choice between ice cream and broccoli, that's not gonna be the ad” 1:29:35
In the concluding segment, the hosts and Hugo Mercier explore the proportion of human verbally articulated beliefs that are intuitive versus reflective. Mercier estimates that the overwhelming majority of durable cultural and scientific beliefs are reflective rather than intuitive, noting the trade-offs between local personal relevance and widespread cultural information.
For things that are more durable, I would say the overwhelming majority uh probably is is reflective.
“For things that are more durable, I would say the overwhelming majority” 1:32:19
Most of the beliefs we have are relevant only to us. Essentially, no one cares
“Most of the beliefs we have are relevant only to us.” 1:34:32
Hosts Dave Pietraszewski and David Pinsof thank guest Hugo Mercier for his time in the evening, and then transition into closing housekeeping. They discuss listener reviews, supporting the show on Patreon, everyday tasks listeners can do with their extra time, and banter about leftover podcast merchandise such as fanny packs and stickers.
The hosts thank Hugo Mercier for recording late in the evening and discuss podcast housekeeping items like reviews and Patreon.
“leave us a kind review or say something nice on” 1:36:52
The hosts banter about needing a fanny pack and having an excess of podcast stickers.
“we're drowning in these stickers we ordered too many” 1:37:31