The conversation, in brief.
In this episode of the podcast, hosts Dave Pietraszewski and David Pinsof are joined by Dr. Keelah Williams to explore the intersection of evolutionary psychology and the legal system. The speakers discuss how legal institutions emerge from evolved psychological mechanisms to regulate behavior and resolve interpersonal conflicts. They examine criminal motive, culpability standards, welfare trade-off ratios, and juror decision-making. Additionally, Dr. Williams shares her research on affordance management theory, resource scarcity, and how environmental ecologies shape public attitudes toward the death penalty, immigration, and behavioral stereotypes.
Through the conversation.
18 sections010:00 – 7:25Introduction to Evolutionary Psychology and Law
Hosts Dave Pietraszewski and David Pinsof introduce guest Dr. Keelah Williams, a professor at Hamilton College with both a PhD and a JD. They discuss the intersection of evolutionary psychology and the legal system, noting how psychological science and legal practice sometimes arrive at contrasting conclusions while examining the general resistance of legal institutions to change.
The goal of evolutionary psychology in particular is to understand human behavior. And the goal of law is to regulate it.
“The goal of evolutionary psychology in particular is to understand human behavior.” 7:04
The legal system is very, very slow to incorporate science in general and psychological science in particular.
“the legal system is very, very slow to incorporate science in general and psychological science in particular.” 4:32
027:26 – 12:02Regulating Behavior and the Function of Legal Systems
The hosts and Dr. Keelah Williams discuss whether the legal system is designed to promote justice, concluding that it functions primarily as a mechanism for behavior regulation and coordination rather than an efficient producer of equal or idealized outcomes.
Depending on your definition of justice, if that is what you want to see, then I don't think that the legal system is well designed to produce those outputs.
“I don't think that the legal system is well designed to produce those outputs.” 9:54
0312:02 – 17:09Evolutionary Psychology and the Foundations of Legal Systems
Dave Pietraszewski, David Pinsof, and guest Keelah Williams discuss how legal institutions emerge from evolved psychological mechanisms to resolve interpersonal conflicts, contrasting this scientific framework with the naive realism often found in traditional legal scholarship.
Keelah Williams explains that modern legal institutions stem from evolved psychological mechanisms shaped by natural and sexual selection.
“these modern legal institutions are stemming from evolved psychological mechanisms.” 13:56
Keelah Williams agrees that evolutionary scientists hold a more realistic view of human cognition compared to the naive perspective of legal scholars.
“I think that's a realistic description of um the differences between how as evolutionary scientists we would think about the ways that people think and behave” 16:13
The hosts and Keelah Williams examine how legal systems differentiate between motive, intent, and various levels of culpability such as recklessness and negligence, while exploring how people's intuitive decision-making intersects with these legal standards.
Keelah Williams notes that strictly speaking in legal terms, criminal motive is not supposed to matter when adjudicating guilt.
“motive, the reason why somebody did what they did, um not supposed to matter when it comes to adjudicating guilt.” 17:39
Keelah Williams confirms that judges are explicitly allowed to use motive information as a mitigating or aggravating factor during sentencing.
“at the sentencing phase judges are explicitly allowed to to use motive information um as both a mitigating or or an and an aggravating factor” 18:20
Host Dave Pietraszewski, David Pinsof, and guest Keelah Williams discuss how legal systems view motive as legally irrelevant yet prosecutors heavily emphasize it during trials. The speakers critique traditional psychological explanations as circular and propose an adaptationist approach, introducing welfare trade-off ratios as a measure of how much someone values another person's well-being.
That's clo classic circular psychology reasoning right there.
“That's clo classic circular psychology reasoning right there.” 25:25
And what we suggested one reason is uh might be because motive matters for assessing association value.
“And what we suggested one reason is uh might be because motive matters for assessing association value.” 26:10
The speakers examine how welfare trade-off ratios explain why certain motives evoke harsher moral judgments than others, using examples like random violence versus targeted conflict. They discuss how evolutionary psychology provides a causal explanation for juror intuitions about perceived threat and future association value.
And so from a legal perspective, what does the law say about welfare trade-off ratios?
“And so from a legal perspective, what does the law say about welfare trade-off ratios?” 30:12
And and I think an evolutionary approach gives you well, one of the benefits is that it gives you an explanation for why that is
“And and I think an evolutionary approach gives you well, one of the benefits is that it gives you an explanation for why that is” 33:43
0736:07 – 39:58Assessing Motives and Future Behavior in Legal Judgment
Keelah Williams, Dave Pietraszewski, and David Pinsof discuss theoretical implications for empirical tests regarding perpetrators' motives, perceived costs and benefits, and future association value. They explore how high-value individuals, such as a top surgeon or someone with stellar character, might face less harsh punishment despite bad motives, comparing it to being too valuable to convict.
Perpetrators with different motives can be seen as similarly responsible yet lead to very different conclusions about punishment based on perceived costs and benefits.
“we can find perpetrators with different motives being similarly responsible for an offense” 36:39
High association value or perceived future benefits can lead observers to punish an offender less harshly, functioning like being too valuable to convict.
“it's like the interpersonal legal version of like the bank's too big to fail” 39:19
0839:58 – 48:11Separating Fact-Finding from Sentencing and Institutional Constraints
The speakers debate whether the legal system should cleanly separate the assessment of guilt from the determination of sentencing. They examine human psychological biases, mandatory minimum sentences, and jury nullification, noting that institutional constraints and human intuition often blend factual evaluation with value judgments.
Distinguishing between establishing what is true and determining how badly a person deserves to be punished helps avoid bias in fact-finding.
“when you're thinking about whether the person did it versus how much how badly they should be punished” 40:30
Jury nullification occurs when juries conclude a defendant committed an act but choose to return a not-due verdict due to mitigating circumstances or institutional constraints.
“It's called jury nullification when it's juries who are doing it” 45:20
The hosts and guest Keelah Williams discuss how psychological cues and association values influence juror impartiality during trial proceedings. They examine how attorneys often rely on arbitrary intuitions during jury selection rather than scientific methods, and share personal experiences with avoiding jury duty.
Attorneys rely heavily on intuition during jury selection, using arbitrary criteria like socks or magazine choices to infer juror characteristics.
“they tend to rely really heavily on intuition. Uh, attorneys” 50:05
David Pinsof shares how mentioning his skepticism of eyewitness testimony successfully helped him avoid serving as a juror.
“said I I was skeptical of eyewitness testimony” 53:58
The speakers explore affordance management theory, examining how human psychology evolved to detect threats and opportunities in the environment. Keelah Williams describes her research on how resource scarcity influences public attitudes toward the death penalty and the decision to rehabilitate versus eliminate serious offenders.
Affordance management theory posits that the social mind evolved to identify environmental threats and opportunities and respond in adaptive ways.
“affordance management theory, the idea that the goal of the social mind is to identify threats” 55:14
Research shows that resource scarcity increases people's willingness to impose the death penalty on serious offenders rather than rehabilitate them.
“the amount of available resources in the environment is going to affect that calculus” 57:59
Hosts Dave Pietraszewski and David Pinsof discuss with guest Keelah Williams whether perceived resource scarcity drives public support for capital punishment. They examine whether informing people about the actual legal costs of the death penalty alters their views, noting that explicit cost information does not shift decisions because the mind may operate on deeper intuitive logics.
it is true that killing someone in America with the death penalty is more expensive than keeping them alive for life
“So it is true that killing someone in America with the death penalty is more expensive than keeping them alive for life.” 1:01:14
And that did not actually push around their their death penalty decisions
“And that did not actually push around their their death penalty decisions.” 1:02:34
Keelah Williams and the hosts explore global data relating human development indices to capital punishment and discuss how zero-sum competition rather than absolute wealth drives punitive attitudes. They also discuss experimental findings showing that the perceived value of an offender, such as being a skilled hunter, moderates willingness to banish group members during scarcity.
resource scarcity doesn't make people more punitive in general, that it doesn't just heighten their their desire to punish and punish harshly
“resource scarcity doesn't make people more punitive in general, that it doesn't just heighten their their desire to punish and punish harshly” 1:05:12
when resources are scarce, people actually became much less willing to ban it was banishment in this case, to banish the hunter from the group
“when resources are scarce, people actually became much less willing to ban it was banishment in this case, to banish the hunter from the group.” 1:11:30
Dave Pietraszewski, David Pinsof, and guest Keelah Williams discuss how immigrant characteristics like skill level and religion shape public attitudes and eliminate partisan divides. They explore the evolutionary logic of zero-sum competition, association value, and how demagogues exploit resource perceptions in political rhetoric.
association value and high resources should go together in like rhetoric about like outgroups
“association value uh and high resources should go together in like uh rhetoric about like outgroups” 1:14:34
Keelah Williams explains her research with Oliver Sung and Steve Newberg on ecology stereotypes, detailing how people infer psychological traits like present- or future-focus from environmental resource scarcity. The speakers discuss how separating race and ecology information can eliminate racial stereotype effects.
people grow up in environments that are resource poor and unpredictable, that they this tends to engage more present-focused strategies
“that when people grow up in environments that are resource poor and unpredictable, that they this tends to engage more present-focused strategies.” 1:17:11
people's stereotypes tracked ecology and not race. So it essentially wiped out the effect of the race stereotypes
“that people's stereotypes tracked ecology and not race. So it essentially wiped out the effect of the race stereotypes.” 1:21:19
Dave Pietraszewski, David Pinsof, and guest Keelah Williams discuss the hidden psychological machinery underlying legal and political decisions, exploring how racial categories and family structures act as proxies for tracking environmental ecologies and impulsivity across different cultures and species.
people have used the phrase deep rationality. And I think it's a good one.
“People have used the phrase deep rationality. And I think it's a good one.” 1:25:16
we very recently published a paper that shows that ecology stereotypes are quite universal.
“we very recently published a paper that shows that ecology stereotypes are quite universal.” 1:29:19
David Pinsof and Keelah Williams address skepticism and common critiques of the ecology framework, emphasizing that the theory is fundamentally anti-essentialist, applies across different species, and provides a deeper causal explanation for social class and behavioral stereotypes.
the work is saying quite the opposite. It's saying that there's nothing about blackness that makes people impulsive
“the work is saying quite the opposite. It's saying that there's nothing about blackness that makes people impulsive” 1:33:12
Whereas we are claiming that you do see across species these ecology effects.
“Whereas we are claiming that you do see across species these ecology effects.” 1:34:24
Dave Pietraszewski, David Pinsof, and guest Keelah Williams discuss how cultural items and behaviors function to signal class membership, status, and ecology stereotypes such as present-orientedness. They explore intersections with age stereotypes and conclude the scientific discussion by highlighting key readings and researchers in evolutionary approaches to the law.
It was the elephant in the top hat.
“It was the elephant in the top hat.” 1:36:50
So that I think is cool work that I would like people to be aware of.
“So that I think is cool work that I would like people to be aware of.” 1:41:18
The hosts thank Keelah Williams for joining the program to share her cutting-edge work on evolutionary psychology and the law. In their closing remarks, Dave and David humorously discuss philosophical vocabulary like supererogatory and subdoxastic before encouraging listeners to support the podcast through social media, reviews, and Patreon.
A passage from this discussion.
“When I think of like who's the usual suspects doing fantastic cutting edge experimental” 1:42:55