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EPISODE 51 / Apr 28, 2026

Sex and Gender with Dan Conroy-Beam

Dan Conroy-Beam·2h 06m·23 sections
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Audio from the publisher. Timestamps reference the archived recording.

THE SHAPE OF THE CONVERSATION

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The conversation, in brief.

Hosts Dave Pietraszewski and David Pinsof are joined by guest Dan Conroy-Beam to explore the evolutionary biology of sex and gender using agent-based modeling. The discussion addresses limitations in traditional psychological and anthropocentric definitions of sex, proposing instead that biological sex arises from a quality-quantity trade-off in gamete production. The conversation examines how ecological demands and pathogen pressures shape sexual reproduction, divisions of labor, and mating strategies. Furthermore, the speakers conceptualize gender as an individual's folk theory or mental model of how sex manifests within a specific ecology, shaped by social learning and environmental stability.

QUESTIONS TO KEEP IN MIND

  • How does agent-based modeling help researchers uncover hidden assumptions in psychological theories?
  • In what ways do standard psychological definitions of sex differ from evolutionary perspectives based on gamete production?
  • How do pathogens and coevolutionary arms races influence the evolutionary origins of sexual reproduction?
  • What role do ecological pressures and environmental stability play in shaping the sexual division of labor?
  • How can gender be understood as a continuum of adaptive strategies rather than a strict binary?

Ideas to take with you.

  • Agent-based modeling is a useful computer simulation technique that allows researchers to study complex social dynamics by simulating autonomous entities and making theoretical assumptions explicit. 6:21
  • Psychological definitions of sex are frequently criticized as overly anthropocentric and inadequate for capturing biological realities across diverse species. 28:24
  • Biological sex emerges from an inevitable quality-quantity trade-off in gamete production, leading to specialized adaptations for small and large gametes. 40:17
  • Gender can be defined as a set of folk theories or individual mental models regarding how sex manifests in a particular local ecology. 1:08:53
  • Environmental stability influences whether parents impose gender concepts through policing strategies to socialize offspring. 1:44:17

Through the conversation.

23 sections
01
0:00 – 9:00

Introduction to Sex, Gender, and Agent-Based Modeling

Hosts Dave Pietraszewski and David Pinsof introduce repeat guest Dan Conroy-Beam, discussing his work on the evolutionary biology of sex, sex roles, and gender. They explore the value of agent-based modeling as a computer simulation technique for studying complex social phenomena and individual psychology.

agent based modeling is just one technique for formally modeling psychological hypotheses

“agent based modeling is just one technique for formally modeling psychological hypotheses” 6:10

it's a computer simulation technique where what you do is you simulate populations of autonomous entities

“It's a computer simulation technique where what you do is you simulate populations of autonomous entities” 6:21
02
9:01 – 12:02

Advantages of Agent-Based Modeling in Social Systems

The speakers discuss how agent-based models allow researchers to bypass complex advanced mathematics by simulating individual decision rules and observing emergent social behaviors. This approach offers a realistic representation of systems with many interacting parts and forces researchers to make their assumptions explicit.

agent-based modeling is a really good technique if you are interested in building formal models, but like me are not particularly skilled at math

“agent-based modeling is a really good technique if you are interested in building formal models, but like me are not particularly skilled at math” 9:49

it forces you to be explicit about things

“And it forces you to be explicit about things.” 11:29
03
12:02 – 19:30

The Value of Formal Modeling and Agent-Based Simulation

Guest Dan Conroy-Beam and hosts Dave Pietraszewski and David Pinsof discuss the limitations of purely verbal theorizing in psychology and how formal agent-based models uncover hidden assumptions. Conroy-Beam shares how trying to understand mating psychology and speed-dating dynamics through computer simulations led to his current methodological approach, inspired by Richard Feynman's dictum about creation and understanding.

I've never sat down to write an agent-based model and not realized an assumption I didn't realize I was making

“I've never sat down to write an agent-based model and not realized an assumption I didn't realize I was making.” 12:13

so much of our theorizing in psychology is purely verbal

“so much of our theorizing in psychology is purely verbal.” 12:32
04
19:30 – 24:05

Modeling the Evolution of Sex and Gender

The speakers explore Conroy-Beam's current sabbatical project involving agent-based models on the evolution of sex and gender. They discuss how evolutionary biology models sex through parental investment and reproductive rates, while considering whether gender functions as a cultural signaling mechanism for underlying reproductive strategies.

we have a bunch of evolutionary models on the evolution of sex

“we already have a bunch of evolutionary models on the evolution of sex.” 22:13

maybe gender is like how you signal this

“maybe gender is like how you signal this” 22:47
05
24:06 – 30:43

Critiques of Psychological Definitions of Sex and Gender

Guest Dan Conroy-Beam and hosts discuss the inadequacies of standard psychological definitions of sex and gender. Conroy-Beam argues that definitions from institutions like the APA are overly anthropocentric, rely on flawed indicators like chromosomes or genitalia, and fail to capture biological realities across the diversity of life or offer clear distinctions regarding gender.

the definitions of sex that like psychologists use are really, really anthropocentric and don't capture like the concept of sex more broadly

“the definitions of sex that like psychologists use are really, really anthropocentric and don't capture like the concept of sex more broadly” 28:24

people will offer definitions of gender that are literally like, you know, aspects of femininity.

“people will offer definitions of gender that are literally like, you know, aspects of femininity.” 29:31
06
30:43 – 36:11

Agent-Based Modeling and the Evolutionary Origins of Sex

The speakers explore Dan Conroy-Beam's agent-based models investigating the evolutionary origins of sexual reproduction. Conroy-Beam explains how he used agent-based simulations to test hypotheses about why sexual reproduction evolved despite its inherent costs, focusing on coevolutionary arms races between hosts and pathogens.

Asexual reproduction just seems like the better way to reproduce. Like you don't have to pay all the costs of searching for a mate.

“Asexual reproduction just seems like the better way to reproduce. Like you don't have to pay all the costs of searching for a mate.” 32:34

John's idea was that it has to do with pathogens, right? Like so we're all in this long standing coevolutionary arms race with pathogens.

“John's idea was that it has to do with pathogens, right? Like so we're all in this long standing coevolutionary arms race with pathogens.” 33:47
07
36:11 – 37:22

Evolution of Sexual Reproduction and Pathogens

Dave Pietraszewski, David Pinsof, and guest Dan Conroy-Beam discuss the evolutionary origins of sexual reproduction, highlighting how selection pressures like pathogens shaped fundamental biological mechanisms rather than modern everyday conveniences.

the idea that like we're built around the fact that pathogens exist

“the idea that like we're built around the fact that pathogens exist” 36:51

you are designed around and to defeat pathogens

“you are designed around and to defeat pathogens” 37:04
08
37:23 – 48:13

Evolution of Sexes and Gamete Size Trade-offs

Dan Conroy-Beam explains how the evolution of sexes emerges from a quality-quantity trade-off in gamete production, where agents evolve bimodal distributions of large and small gametes based on energy budgets and reproductive strategies.

There's going to be an inevitable sort of quality-quantity trade-off in gamete production.

“There's going to be an inevitable sort of quality-quantity trade-off in gamete production.” 40:17

what sex is, is there is this inevitable quality-quantity trade-off in gamete production.

“what sex is, is there is this inevitable quality-quantity trade-off in gamete production.” 43:03
09
48:13 – 54:10

Evolutionary Models of Gametes, Competition, and Parenting

Guest Dan Conroy-Beam discusses evolutionary models examining how gamete production strategies shape sex differences in mate competition and parenting behavior. He explains with attribution to evolutionary principles that small gamete producers are favored to engage in costly competition, whereas large gamete producers evolve higher parental investment adaptations, though these outcomes depend heavily on ecological assumptions like sex ratios and travel time.

selection should favor those kinds of costly competition genes in the small gamete producers

“selection should favor those kinds of costly competition genes in the small gamete producers” 49:01

at the same time that selection is favoring mate competition in the small gamete producers, it favors the evolution of these like costly parenting adaptations in the large gamete producers

“At the same time that selection is favoring mate competition in the small gamete producers, it favors the evolution of these like costly parenting adaptations in the large gamete producers.” 50:53
10
54:10 – 1:00:17

Defining Sex, Abstractions, and Evolved Psychological Intuitions

David Pinsof and Dan Conroy-Beam explore what defines biological sex, considering phenomena like sex-role reversals in phalaropes and concluding that gamete production provides a universal definition. They argue that sex operates as an abstract conceptual optimum shaped by selection and ecology rather than a fixed physical trait, while noting that human psychological intuitions about sex create challenges for scientific understanding.

gametizes is like a clean, universal universal, universally applicable definition

“gametizes is like a clean, universal um uh universal, universally applicable definition.” 56:43
11
1:00:18 – 1:06:57

Defining Biological Sex and Evolutionary Optima

Host Dave Pietraszewski, David Pinsof, and guest Dan Conroy-Beam discuss the biological definition of sex, debating whether it should be framed around adaptations or as the equilibrium of selection pressures on gamete size. They also differentiate sex from sex roles such as parental investment and competition.

Sex is the set of adaptations that specialize in either large or small gametes.

“Sex is the set of adaptations that specialize in either large or small gametes.” 1:03:53

What sex is is just like whatever are the optima for this particular species.

“what sex is is just like whatever are the optima for this particular species” 1:05:38
12
1:06:57 – 1:12:19

The Concept of Gender and Human Foraging Niches

The speakers transition to discussing gender, which Dan Conroy-Beam defines as a set of folk theories about how sex manifests in a particular ecology. They explore how human adaptability across diverse foraging niches requires learning local subsistence strategies, technologies, and social structures.

Gender is a sort of set of folk theories about how sex manifests in your particular ecology.

“what gender is, is a sort of set of folk theories about how sex manifests in your particular ecology.” 1:08:53

Humans live in all inhabitable ecologies on this planet plus Canada and New Jersey.

“humans live in all you know inhabitable ecologies on this planet plus Canada. And New Jersey.” 1:09:36
13
1:12:19 – 1:19:15

Ecological Adaptations and Human Lifeways

Dave Pietraszewski, David Pinsof, and Dan Conroy-Beam discuss how humans act as intuitive socioecologists, learning lifeways and foraging strategies adapted to their local ecology over generations rather than evolutionary time. They also examine how status games are tethered to ecological resources and the developmental psychology of learning these cultural practices.

sociioecology tends to study the relationships between ecology and social structure that emerge over evolutionary time

“socioecology tends to study the relationships between ecology and social structure that emerge over evolutionary time.” 1:13:10

the genes need to build one psychology that can work in any kind of ecology

“the genes need to build one psychology that can work in any kind of ecology.” 1:17:44
14
1:19:16 – 1:24:22

Sex Differences, Division of Labor, and Gender

Dan Conroy-Beam explains how biological sex differences, such as internal gestation and lactation, interact with ecological demands to shape sexual divisions of labor and optimal lifeways. The speakers also consider how psychological predispositions, such as risk-taking, contribute to the development of gender roles and cultural lifeways.

what gender is is like your models of like what is the life way in my particular ecology separated by sex

“what gender is is like your models of like what is the life way in my particular ecology separated by you know sex.” 1:22:04
15
1:24:22 – 1:32:50

Agent-Based Modeling of Foraging and Social Learning

Dan Conroy-Beam and the hosts discuss computational models of agents managing households, gathering resources, and balancing parenting with foraging. Conroy-Beam explains how environmental predictability shapes whether selection favors genetically encoded foraging strategies or reinforcement learning mechanisms, highlighting how social learning allows agents to adapt to ecological demands.

In that kind of environment, selection favors a genetically encoded foraging strategy.

“In that kind of environment, selection favors a genetically encoded foraging strategy.” 1:29:31

Selection favors the learning agents that learn from adults in a sex differentiated way.

“selection favors the learning agents that learn from adults in a sex differentiated way.” 1:32:32
16
1:32:50 – 1:36:23

The Psychology of Gender and Computational Models

The speakers explore how these computational models provide theoretical teeth for understanding gender identity and expression. Dan Conroy-Beam suggests that gender represents an individual's model of how sex manifests in their specific ecology, connecting evolutionary history and developmental psychology.

What gender is is your model of how sex manifests in the particular ecology where you happen to have been born.

“what gender is is your model of how sex manifests in the particular ecology where you happen to have been born.” 1:32:54

Kids for very good reason are born with an expectation that gender is probably a thing that shapes lifeways.

“kids for very good reason are born with an expectation that gender is probably a thing that shapes lifeways.” 1:34:44
17
1:36:24 – 1:39:24

Intrasexual Competition and Gender Expression

Dave Pietraszewski, David Pinsof, and guest Dan Conroy-Beam explore how intrasexual competition and sexual divisions of labor shape gender expression and signaling. They discuss how members of each sex signal prototypical traits such as strength, risk-taking, health, and fertility to attract mates and navigate social roles.

women would have an interest in mating with the best big game hunters, and men would have an interest in mating with the best gatherers.

“women would have an interest in mating with the best big game hunters, and” 1:37:26

it seems like there there is selection within each sex to signal a kind of prototypicality.

“it seems like there there is selection within each sex to signal a kind of” 1:38:28
18
1:39:25 – 1:48:27

Gender Policing, Social Conflict, and Parent-Offspring Dynamics

The speakers discuss why individuals care about others' gender concepts, focusing on mating markets, offspring socialization, and environmental stability. Dan Conroy-Beam explains a model of gender policing where parents intervene in offspring behavior based on environmental stability, which can generate cultural conflicts and intergenerational tensions over mate preferences and lifeways.

when environments are stable, selection favors this kind of like policing strategy of like impose your gender concept onto your offspring.

“when environments are stable, selection favors this kind of like policing strategy of like impose your gender” 1:44:17
19
1:48:27 – 1:50:55

Niche Construction and Individual Differences in Lifeways

Host Dave Pietraszewski, David Pinsof, and guest Dan Conroy-Beam discuss how individuals tailor their life ways and strategies based on their unique inherited traits and ecologies, linking individual differences and niche construction to gender and behavioral strategies.

there's an individual difference angle that I'm also sort of like under exploring

“an individual difference angle that I'm also sort of like under exploring” 1:49:53

Like the body you happen to inherit is gonna shape what is the the right way to do things for you

“the body you happen to inherit is gonna shape what is the the right way to do things for you” 1:50:23
20
1:50:56 – 1:58:09

Continuum of Gender, Alternative Strategies, and Social Selection

The speakers examine gender as a continuum rather than a strict binary, exploring how ecological pressures and learning generate multiple optimal strategies within sexes, which subsequently influences mate preferences, mentorship, and friendship dynamics.

gender is not merely a dichotomy but a continuum

“gender is not merely a dichotomy but a continuum” 1:50:56

you don't need to think about gender as being binary

“you don't need to think about gender as being binary” 1:52:23
21
1:58:09 – 2:00:29

Reflecting on Podcast Themes and Closing Conversation

The hosts and Dan Conroy-Beam reflect on the scope of the manuscript, its connections to developmental psychology, and wrap up the episode with lighthearted banter about podcast traditions and future episodes.

I find this like it connects so much area so many areas of developmental psychology

“it connects so much area so many areas of developmental psychology” 1:58:24
22
2:00:29 – 2:02:41

Framing the Paper as a Synthesis of Gender

Dave Pietraszewski, David Pinsof, and guest Dan Conroy-Beam discuss how to frame Dan's upcoming paper. Rather than being self-indulgent, they agree that starting from evolutionary first principles provides a valuable causal framework and a much-needed synthesis of gender for the field.

You're doing this form like really methodically, logically.

“You're doing this form like really methodically, logically.” 2:01:13

And I do think it's a contribution to provide a causal framework attached to all these different pieces.

“And I do think it's a contribution to provide a causal framework” 2:01:52
23
2:02:42 – 2:06:07

Conference Swag and Future Podcast Plans

The hosts wrap up the episode by discussing conference swag options for the upcoming HBES meeting, joking about expensive items like plush toys, and considering recording short man-on-the-street style interviews with attendees at the conference.

Do you you think stickers is the way to go in terms of the the stuff to hand out?

“Do you you think stickers is the way to go” 2:03:13

So sort of like man on the street kind of thing.

“man on the street kind of thing.” 2:04:44