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EPISODE 36 / Jan 13, 2026

Peace with Luke Glowacki

Luke Glowacki·1h 53m·20 sections
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The conversation, in brief.

In this episode of the podcast, hosts Dave Pietraszewski and David Pinsof are joined by guest Luke Glowacki to discuss the evolutionary origins and cultural mechanics of intergroup conflict and peace. Glowacki shares insights from his fieldwork among the Nyangatom in East Africa and his academic background in biological anthropology. The conversation explores human stranger tolerance, Richard Wrangham's imbalance of power hypothesis, fission-fusion social dynamics, low-cost small-scale raids, and the collective action challenges of establishing and maintaining durable peace. They also debate whether moralization plays a causal role in intergroup violence and touch upon Glowacki's upcoming book manuscript, 'Enemy Eaters,' and his research projects in the Omo Valley.

QUESTIONS TO KEEP IN MIND

  • How does human tolerance toward strangers differ from the social structures observed in other primates like chimpanzees and bonobos?
  • What role do cultural technologies and social norms play in solving the collective action problem of establishing peace?
  • Why do decentralized conflicts in small-scale societies predominantly take the form of low-risk raids rather than large-scale warfare?
  • Is moralization a necessary causal mechanism for intergroup violence, or is it an epiphenomenal narrative framing?
  • How do communities use social enforcement, leadership censure, and execution to deter rogue actors from breaking peace agreements?

Ideas to take with you.

  • Humans possess an unusual capacity for stranger tolerance compared to other social primates. 14:24
  • Richard Wrangham's imbalance of power hypothesis offers a compelling framework for understanding coalitionary violence. 23:41
  • Decentralized conflict in small-scale societies most commonly manifests as low-risk, small-group raids. 48:15
  • Achieving and maintaining peace presents a difficult collective action problem that requires aligning incentives within a society. 1:03:04
  • Intergroup exchange and peace act as critical engines driving cumulative cultural evolution. 1:34:33

Open questions & qualifications

  • David Pinsof and Luke Glowacki debated whether moralization and narrative framing play a necessary causal role in intergroup violence, with Pinsof arguing they manage reputational costs and coordination while Glowacki pointed to bounded moral universes where violence occurs without elaborate pretexts. 1:15:58

Through the conversation.

20 sections
01
0:00 – 5:43

Introduction and Luke Glowacki's Academic Background

Hosts Dave Pietraszewski and David Pinsof introduce guest Luke Glowacki, discussing his academic lineage connected to Jane Goodall and Richard Wrangham, his training in biological anthropology at Harvard, and his current position in the anthropology department at Boston University.

my PhD supervisor was Richard Rangam, but Jane Goodall was not technically Richard's PhD supervisor

“my PhD supervisor was Richard Rangam, but Jane Goodall was not technically Richard's PhD supervisor” 3:36
02
5:43 – 12:00

Transition to Evolutionary Behavioral Sciences and the Evolution of Peace

Luke Glowacki describes his journey from studying philosophy to discovering evolutionary behavioral sciences through a critic's book. The conversation then transitions to his recent paper, 'The Evolution of Peace,' exploring how culture bridges the gap between evolutionary biology and psychological processes in intergroup conflict and cooperation.

I thought the closest you could get to understanding human cognition was Kant

“I thought the closest you could get to understanding human cognition was Kant, you know, just deep reflection about the structures of the mind” 6:13

we don't have a lot of sort of theory like linking sort of our evolutionary biological explanations

“we don't have a lot of sort of theory like linking sort of our evolutionary biological explanations, say for a psychology for dominance or for status” 10:40
03
12:01 – 17:20

Defining Human Tolerance and Evolutionary Foundations of Peace

Dave Pietraszewski, David Pinsof, and guest Luke Glowacki discuss how human tolerance of strangers and peaceful interaction with unknown individuals differ from other social primates like chimpanzees and bonobos. They explore the evolutionary and comparative biology perspectives, examining whether peace and intergroup conflict rely on cultural technologies and ancestral behavioral states.

Humans are extremely unusual for our capacity for so the term that's often used is tolerance, just to tolerate strangers

“So humans are extremely unusual for our capacity for so the term that's often used is tolerance, just to tolerate strangers” 14:24
04
17:20 – 24:04

Intergroup Conflict, Imbalances of Power, and Animal Models

The hosts and Luke Glowacki examine whether other species engage in lethal intergroup violence without power imbalances, discussing examples like bandit mongooses. They analyze how expected costs and benefits drive coalitionary violence, contrasting chimpanzee attacks with mongoose scrum dynamics and Richard Wrangham's imbalance of power hypothesis.

The imbalance of power hypothesis, I think is just one of the sort of like most beautiful, elegant theories out there

“the imbalance of power hypothesis, I think is just one of the sort of like most beautiful, elegant theories out there” 23:41
05
24:04 – 30:07

Fission-Fusion Dynamics and the Evolutionary Origins of War

Dave Pietraszewski, David Pinsof, and guest Luke Glowacki discuss the ecological and social conditions that give rise to lethal intergroup violence across species. They explore fission-fusion social structures, resource distribution, and why certain animals like chimpanzees engage in coalitionary aggression while others do not.

you have a grouping pattern that's not a true there, it's fission fusion where so you can think of humans where you spend a lot of time in a large group, but people are often coming and going.

“fission fusion where so you can think of humans where you spend a lot of time in a large group, but people are often coming and going” 24:44

And so is is the the idea that we we don't see this in in say herbivores that that eat grass, it's it's because the distribution of resources is not very lopsided.

“the distribution of resources is not very lopsided” 29:39
06
30:07 – 36:04

Ecological Pressures, Psychology, and Preconditions for Conflict

The hosts and Luke Glowacki examine whether carnivory is a necessary precondition for coalitionary violence and the evolution of war. They discuss how group-living psychology, resource defense, and territoriality interact to determine which species develop cooperative aggression.

In order to wage war, you have to have a psychology to you to engage in coalitionary aggression, use it strategically. So that requires certain evolutionary preconditions to be met.

“in order to wage war, you have to have a psychology to you to engage in coalitionary aggression” 32:20

no, I don't think it's necessary. I think you know, I think there is something appealing sort of about you know hunting as a pathway to war.

“I think there is something appealing sort of about you know hunting as a pathway to war” 33:16
07
36:04 – 42:57

Evolutionary theories of coalitionary violence

Hosts Dave Pietraszewski and David Pinsof discuss the evolution of coalitionary violence with guest Luke Glowacki, examining why multi-agent conflict is zoologically rare, the computational and strategic challenges of forming stable coalitions, and how new data requires a refinement of existing theoretical models across species.

our theorizing on the evolution of coalitionary violence, lethal coalitionary violence, it's not as refined as it should be in the in the wake of just a lot of other data on species coming out.

“our theorizing on the evolution of coalitionary violence, lethal coalitionary violence, it's not as refined as it should be in the in the wake of just a lot of other data on species coming out.” 38:57
08
42:57 – 48:09

The challenge of achieving peace in decentralized conflict

Guest Luke Glowacki shares fieldwork observations among the Nyangatom in East Africa, leading to the insight that because war can easily offer tangible benefits like resources and status, the harder theoretical question is understanding how groups successfully stop fighting and establish peace.

A passage from this discussion.

“like situation, how do you get groups to stop fighting?” 46:08
09
48:09 – 58:46

Ancestral Conflict Patterns and Small-Scale Raids

Host Dave Pietraszewski and guest Luke Glowacki discuss the nature of intergroup conflict in small-scale societies, noting that decentralized conflict typically takes the form of low-risk raids rather than large-scale warfare. They examine the costs and benefits of these raids, comparing human patterns to those of other species like chimpanzees, and discuss how modern technologies like firearms and cell phones influence these traditional behaviors.

The most common type of attack across the ethnographic literature and decentralized conflict is the raid.

“the most common type of attack across the ethnographic literature and decentralized conflict is the raid” 48:15

Small-scale raids are characterized by low risk and low cost to the attackers, similar to chimpanzee patrols.

“small group of individuals goes out at less at low cost to themselves” 53:39
10
58:47 – 1:00:11

Scaling Up From Small Raids to Large-Scale Warfare

David Pinsof and Luke Glowacki explore the disconnect between evolved human psychology designed for low-cost, small-scale raids and the large-scale warfare seen in civilization with formal armies and states. They draw an analogy between large-scale warfare and large-scale peace treaties or international diplomacy, prompting a discussion about whether analogous mechanisms exist at the small scale.

There is a significant disconnect between small-scale raids driven by power imbalances and the large-scale warfare of states.

“it seems like there's a pretty big disconnect between, you know, the types of intergroup violence that say the imbalance of power hypothesis would explain” 58:47
11
1:00:11 – 1:07:34

The Challenges of Maintaining Peace and Group Level Norms

Dave Pietraszewski, David Pinsof, and guest Luke Glowacki discuss the evolutionary and cultural challenges of maintaining peace between groups, focusing on how small-scale societies struggle with individual rogue actors reinitiating cycles of violence and the difficulty of enforcing group-level norms without centralized institutions.

the central challenge for any society that's gonna any human society that's gonna have peace is how do we align our incentives enough

“the central challenge for any society that's gonna any human society that's gonna have peace is how do we align our incentives enough” 1:03:04

sustained, iterated, you know, durable, harmonious relationships, because it really breaks down very easily.

“sustained, iterated, you know, durable, harmonious relationships, because it really breaks down very easily.” 1:05:42
12
1:07:34 – 1:12:12

Dehomogenizing Groups and the Mechanics of Intergroup Conflict

The speakers examine why people often attribute collective blame to out-groups and how modern societies differ from decentralized tribal groups in their ability to coordinate, dehomogenize groups, and extend moral boundaries beyond immediate kin and in-group members.

many traditional societies, sort of the moral boundaries stop at your group, however your group is defined.

“many traditional societies, sort of the moral boundaries stop at your group, however your group is defined.” 1:10:38

peace is the solution to a collective action problem, to a really hard collective action problem

“peace is the solution to a collective action problem, to a really hard collective action problem” 1:12:02
13
1:12:12 – 1:14:56

Internal Tensions and Social Enforcement of Peace

Dave Pietraszewski, David Pinsof, and guest Luke Glowacki discuss the internal tensions within societies regarding peace versus conflict. They examine how future-oriented versus present-oriented members view raiding, and how communities use norms, leadership censure, ritual specialists, and even physical intervention to align incentives and deter young men from breaking peace agreements.

So society has to figure out a a way to solve these things and come to a consensus

“So society has to figure out a a way to solve these things and come to a consensus” 1:12:55

prominent leaders berating the young men. Don't go on a raid.

“prominent leaders berating the young men. Don't go on a raid.” 1:13:50
14
1:14:57 – 1:24:13

The Causal Role of Moralization in Intergroup Conflict

David Pinsof and Luke Glowacki debate whether moralization, dehumanization, and narratives play a necessary causal role in intergroup violence or if they are merely epiphenomenal. Pinsof argues that moral justifications and narrative framing are necessary to manage reputational costs and coordinate collective action among humans, whereas Glowacki highlights ethnographic examples of bounded moral universes where violence occurs without elaborate pretexts.

I don't think they're I don't think they're a mod modern phenomena, but I think the question is whether they're causal.

“I don't think they're I don't think they're a mod modern phenomena, but I think the question is whether they're causal.” 1:15:58

your moral universe really does is often limited to just people of your own group.

“your moral universe really does is often limited to just people of your own group.” 1:19:25
15
1:24:13 – 1:30:39

Modern Social Environments and Moralistic Inferences

Dave Pietraszewski, David Pinsof, and guest Luke Glowacki discuss how evolved psychology handles ingroup cooperation and outgroup hostility, contrasting small-scale societies with modern social environments where promiscuous moral inferences about character are more common due to large networks and abundant social options.

in small-scale societies you can never like burn a bridge or fully extract yourself from a relationship because the webs of interdependence are just so deep

“in small scale societies you can never like burn a bridge or fully extract yourself” 1:29:24
16
1:30:40 – 1:36:15

The Cost-Benefit Logic and Enforcement of Peace

The speakers examine the definition and mechanics of intergroup peace, noting that establishing peace requires overcoming collective action problems, enforcing norms against outliers, and building centralization. Luke Glowacki explains that intergroup peace unlocks positive-sum relationships that fuel cumulative cultural evolution, while also carrying the potential for scaled-up conflict.

peace is a state of relatively harmonious, durable interactions where there's not the expectation of violence or if violence or aggression occurs, it's aberrant

“a state of like relatively harmonious, durable um interactions where there's not the expectation of violence” 1:31:04

intergroup exchange is one of the engines that drives cultural evolution

“intergroup exchange is one of the engines that drives cultural evolution.” 1:34:33
17
1:36:15 – 1:44:07

Evolution, Cultural Technologies, and Small-Scale Intergroup Relations

Guest Luke Glowacki discusses with hosts Dave Pietraszewski and David Pinsof how peace acts as a cultural technology invented to solve coordination problems. They explore evolutionary psychology, the enforcement of peace through executing rule-breakers, power imbalances, and the ethnography of patron-client relationships among small-scale societies.

the invention of piece. We invented it, we invented these technologies

“the invention of piece. We invented it, we invented these technologies” 1:36:30

a critical mechanism of peace in this in the small-scale societies is the execution

“a critical mechanism of peace in this in the small-scale societies is the execution” 1:39:08
18
1:44:08 – 1:48:17

The Omo Valley Research Project and Giving Back to Host Communities

The hosts and guest Luke Glowacki discuss his ongoing work with Zach Garfield on the Omo Valley Research Project, highlighting educational support, scholarships, and digital skills workshops provided to students in pastoralist communities in Ethiopia.

people often focus on that while ignoring the fact that these are like people just like you and me

“people often focus on that while ignoring the fact that these are like people just like you and me” 1:44:47

what people commonly ask for is that, you know, the students from their communities that have made it through high school

“what people commonly ask for is that, you know, the students from their communities that have made it through high school” 1:45:26
19
1:48:18 – 1:50:36

Luke Glowacki Discusses His Book and Fieldwork

Guest Luke Glowacki chats with hosts Dave Pietraszewski and David Pinsof about his current book manuscript on war and peace. Glowacki explains how his perspective has evolved from a behavioral ecological approach to examining cultural mechanisms of warfare, including the cultural significance of the working title "Enemy Eaters" among tribal societies.

working on a book manuscript trying to sort of describe some of my own personal field work experiences

“working on a book manuscript trying to sort of describe some of my own personal” 1:48:33

tentative title actually is uh Enemy Eaters, because in among tribal societies, many times, eating is a verb that does a lot of work.

“tentative title actually is uh Enemy Eaters, because in among” 1:49:19
20
1:50:39 – 1:52:32

Podcast Outro and Patreon Support

Hosts Dave Pietraszewski and David Pinsof wrap up the episode by discussing ways listeners can support the show, including leaving reviews, interacting on social media, and contributing on Patreon to potentially fund episode editing.

Well, they can say kind things about us on social media. They can leave us a kind review.

“They can leave us a kind review.” 1:50:49

if we raise enough money, we could hire someone to edit us and and make us sound uh smarter than we are.

“if we raise enough money, we could hire someone to edit us and” 1:51:41