#1041 - Dr Debra Lieberman - Why Don’t You Have Sex With Your Sister?

3 Jan 2026 · 1 h 9 min · 26 chapters

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In short

Podcast Notes: Modern Wisdom - Episode #1041 with Dr. Debra Lieberman

Episode Title: Why Don’t You Have Sex With Your Sister?

Guest

Dr. Debra Lieberman Air Date: [Insert Date] Host: Chris Williamson

Introduction

  • Dr. Debra Lieberman is an evolutionary psychologist, professor, and researcher.
  • The episode explores the topic of sexual aversion toward close relatives, particularly the evolutionary mechanisms behind incest avoidance.

Key Themes and Discussions

  1. Evolutionary Mechanisms of Incest Avoidance
  2. Humans have an inbreeding avoidance system that is developed from childhood.
  3. Evolution has designed our psychology to prevent mating with close genetic relatives to avoid the risks of genetic abnormalities in offspring.
  1. Kinship Cues in Humans and Animals
  2. Humans and animals use different cues to identify their close relatives:
  3. Humans: Rely on kinship cues learned during upbringing, including language and cultural markers.
  4. Animals: Use physical cues (e.g., smell, markings) to detect potential mating partners and avoid inbreeding.
  5. The importance of shared caregiving experiences, such as breastfeeding, in determining sibling relationships.
  1. The Westermark Effect
  2. This effect suggests that siblings who grow up together develop a sexual aversion towards each other.
  3. The level of co-residence during childhood influences the strength of this aversion.
  1. Genetic Risks and Altruism
  2. Discusses the genetic risks associated with mating among close relatives (e.g., first cousins) and the concept of altruism in kin relationships.
  3. Altruism is driven by the shared genetic investment in offspring survival.
  1. Moral and Ethical Considerations
  2. Examines the moral arguments surrounding consensual incest among adults, exploring societal norms and individual perspectives.
  3. Discusses Jonathan Haidt's experiments on moral reasoning related to incest and the common inability to rationalize this societal taboo.
  1. Crying and Emotional Communication
  2. Explores the evolutionary significance of crying as a means of emotional communication.
  3. Tears serve to signal distress and elicit support from others, benefiting social bonds.
  1. Cultural Differences and Incest
  2. A look into cultural practices such as cousin marriages and their acceptance in various societies.
  3. Discusses how proximity and upbringing can influence perceptions of kinship and attraction.

Key Takeaways

  • Human sexual aversion toward relatives is a product of evolutionary mechanisms designed to promote genetic diversity and health.
  • Kinship detection is vital not only for reproduction but also for social bonding and altruistic behaviors.
  • Crying serves as an important emotional signal, influencing both personal emotional processing and social interactions.
  • Cultural norms significantly impact perceptions of incest, highlighting the complex interplay between biology and societal values.

Additional Resources

  • Follow Dr. Debra Lieberman:
  • Center for Evolutionary Psychology: [Link]
  • Upcoming textbook on evolutionary psychology available by 2026/2027.
  • Modern Wisdom Resources:
  • Reading list of 100 impactful books: [Link]
  • Productivity energy drink Neutonic: [Link]
  • Other podcast episodes featuring prominent thinkers: [Link]

Conclusion Dr. Debra Lieberman provides fascinating insights into the evolutionary psychology of incest avoidance and emotional responses, showcasing the intricate relationship between our biology and social structures.

Written by AI. May contain mistakes. Listen to the episode to check what was said.

Chapters

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Understanding Kinship Cues

0:45 to 1:40

Discussion on how both humans and animals recognize close relatives.

“How do we know who our close genetic relatives are and why is that important?”

Evolutionary Perspective on Incest Avoidance

1:40 to 5:20

Exploration of the evolutionary reasons behind incest avoidance mechanisms.

“So being nice to your close genetic relatives follows from Hamilton's theory of inclusive fitness.”

Mechanisms of Kin Detection in Humans

5:20 to 8:00

How humans identify relatives through various biological cues.

“sure pinning how we determine kinship onto a few genes that happen to govern facial features is the right way to do it.”

Cultural Influences on Incest Avoidance

8:00 to 11:40

Examining cultural norms and their impact on incest avoidance behaviors.

“So if you see pregnancy or breastfeeding, but you don't share the early co-residence window, does that still trigger incest avoidance?”

The Westermark Effect Explained

11:40 to 13:20

Understanding the Westermark effect and its implications on sibling relationships.

“your mom care for your older sibling as a newborn.”

Understanding the Westermark Effect

14:01 to 15:02

Learn about the Westermark effect and its implications for sibling relationships.

“When does the Westmark window start and stop?”

Modern Sibling Relationships and Sperm Donation

15:02 to 16:36

Explore how modern practices, like sperm donation, challenge traditional sibling dynamics.

“Well, it's so I would say that fathers don't recognize their daughters by the Westermark effect.”

Genetic Sexual Attraction Explained

16:36 to 19:34

Discuss the concept of genetic sexual attraction and its psychological basis.

“First, there's no natural sexual aversion that's developed.”

Moral Dumbfounding in Incest Scenarios

19:34 to 22:33

Analyze Jonathan Haidt's experiment on moral judgments regarding incest.

“Are you familiar with the Mark and Julie experiment?”

Gender Differences in Incest Aversion

22:33 to 24:41

Investigate gender differences in disgust responses towards incest.

“You could do it anonymously on the internet.”
Show all 26 chapters

Personal Reflections on Incest Aversion

27:23 to 28:00

Reflect on personal experiences with sibling relationships and disgust responses.

“I don't have the same visceral disgust response that others have about sibling incest.”

The Language of Disgust Among Siblings

28:00 to 31:02

Explore the psychological dynamics of disgust in sibling relationships.

“So I think for most people that have siblings, it's almost like they have a language of disgust that I don't have the understanding of.”

Incest Porn: Audience and Psychology

31:03 to 36:45

Discuss the paradox of incest porn's popularity despite societal disgust.

“People do stuff for money and people do gross stuff all the time.”

From Incest to the Science of Crying

36:46 to 37:35

Transition from incest discussions to the evolutionary purpose of crying.

“And the answer is, you know, we don't exactly know.”

Understanding the Evolutionary Role of Crying

38:50 to 42:00

Examine why crying is an adaptive behavior and its social implications.

“Why would leaking water from your face ever be adaptive?”

The Power of Tears in Communication

42:00 to 43:20

Learn how tears can convey both costs and benefits in relationships.

“an example, the idea that my tears communicate to you, you are starting to impose a cost on me that is threatening your value in this relationship as well.”

Tears as a Tool of Leverage

43:20 to 44:30

Explore how tears are used by those with less power to influence interactions.

“So it's very much like the scream, but it's used by the lower leveraged in an interaction.”

Crocodile Tears and Manipulation

44:30 to 46:10

Discuss the concept of crocodile tears and their use in manipulation.

“So those are the fun ones where it is people who use tears because they know what they do.”

Tears and Anger: A Gender Perspective

46:10 to 47:30

Analyze the relationship between tears and anger, particularly in women.

“were imposing costs on me and I would really like you to stop.”

The Role of Formidability in Social Dynamics

47:30 to 48:40

Examine how physical formidability influences social interactions and relationships.

“And I don't think, I haven't seen guys get, do the angry cry thing in quite the same way.”

Nonverbal Behavior and Social Hierarchy

48:40 to 51:41

Discover the importance of nonverbal cues in establishing social hierarchies.

“the first thing they do or one of the things they do naturally is they kind of sweep the room, like who else is there?”

Understanding Tears When Alone

52:50 to 55:40

Explore why we cry in solitude and the role of imagination in our emotional responses.

“So if tears are telling another person, I value this thing or you're imposing costs on me and I would like it to stop, why do we cry when we're on our own?”

Crying in Grief and Loss

55:40 to 56:00

Delve into the significance of crying in the context of grief and loss.

“simulating, I think is, or being, you know, showing empathy and putting yourself in the shoes of other people and what you would experience.”

The Psychology of Grief and Tears

56:00 to 1:01:28

Explore the emotional and social functions of crying in response to grief and loss.

“Because let's say somebody's passed away, who are you crying to?”

Crying as a Signal of Emotional States

1:01:28 to 1:06:28

Discuss the varying emotional responses to pain and how crying functions as a signal.

“So things like gratitude, but also depression and sadness and pain.”

Debra Lieberman on Evolutionary Psychology

1:06:28 to 1:07:33

Learn about Debra Lieberman's research in evolutionary psychology and kinship.

“Deb Lieberman, ladies and gentlemen, you're fantastic.”
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Transcript

Automatic transcript. May contain errors.

0:00Why don't people want to have sex with their sister? or their brother or other family members it ends up that humans have a natural inbreeding avoidance system that develops pretty reliably and most folks exposed to the cues which i term kinship cues that are available during childhood um right well what about animals because I understand there is this label, that's your brother, that's your sister. How do animals actually detect who their relatives are? We just take it for granted in humans, you can point and say, but animals don't have language. So how do they know? This is a really good question.

0:42It's always fun to open up an interview with incest, incest avoidance. Incest of you, yeah. Yes. And so it's a really good question. How do we know who our close genetic relatives are and why is that important? Well, first, it's important to know who your close genetic relatives are, not only for the purpose of not mating with them, because mating with close genetic relatives can cause a host of problems. So it leads to less healthy offspring, for instance, and offspring who might suffer from greater genetic mutations. So evolution engineered into our psychology a very sophisticated system to allow us to detect relatives, close genetic relatives, and develop a sexual aversion towards them.

1:28We don't even typically think of them as possible mating partners. It's not foolproof, but this is what tends to happen. And the other reason why we should have a system for naturally detecting and automatically detecting genetic relatedness is for altruism. So being nice to your close genetic relatives follows from Hamilton's theory of inclusive fitness. We're nice to other people as a function. One way altruism can evolve is by being nice to people who tend to share genes by common descent. But you asked the question of, so how do we do this? And because humans aren't the only species that encountered this problem of avoiding mating with close genetic relatives for biological purposes.

2:09And so other animals without language or culture, they use cues, cues that correlated with another individual being a close genetic relative in that species' evolutionary history. So whether it's being part of the same litter or a smell or imprinting on a particular place or a marking, these are the kinds of things that evolution can engineer to help guide kin detection. Humans have language, and so language and culture map very nicely onto these systems, but they're imperfect. And so even though we could join a sorority or fraternity and call people brother, sister, or in certain religions, father, mother, you know who your actual father and mother are.

2:57You know, well, with good certainty, you know who your mom is, who your daddy is, is always an interesting question. But certainly siblings are also individuals who you tend to correctly identify or would have at least in ancestral environments. So we don't use language. Likely, we just use the cues that correlated. And so if you want to go around the horn of the nuclear family to figure out how do we detect who our close genetic relatives are? Well, how do you know who your mother is? This is the female who tended to primarily breastfeed you. So this type of imprinting or mapping onto the female who nursed you.

3:35How does a mom know who her child is? Well, That's kind of, yes, it falls out of you. Unmistakable. How does a child know who her father is? This is not pinned down. I mean, it is a question. I mean, mommy's baby, daddy's maybe. So the question about how it is that people, how does people identify their father really probably goes through understanding who is, who's, have I correctly identified my mother and what males are investing in her because males are going to rely on their paternity certainty in order to direct investment towards their offspring. So relying on what kind of, who's investing in me heavily out there could be one cue that females use, but also the male that was around very early on in development has a better chance of being one's dad than the male that one's mom kind of is hanging out with later on in life.

4:37But it's a really good question. So might phenotype matching occur? It could be. I'm not a fan. What does that mean? So, sorry. That is, do people use facial resemblance as a cue to understand who's likely a relative? That hypothesis does have some interesting data backing it. I'm not a fan of it only because I think ancestrally people looked really similar. Not only that, just by the assortment of genes, siblings can look and fathers can look a lot like their offspring or not as much like their offspring, but still be related, you know, with good certainty. And so I'm not quite sure pinning how we determine kinship onto a few genes that happen to govern facial features is the right way to do it.

5:30But maybe it contributes, to be sure. Certainly, when we see people who look similar to us that can spark a type of kinship. But I think that has more to do with a friendship. In-group, out-group, tribalism. Maybe. Or also, we're always looking for people who might value us and identifying people who share features, any feature. Like, you know, if you were to say, oh my gosh, I have a sister. her name is Debra Lynn, I'd be like, oh my God, I liked you even more. Oh yeah. What's the naming effect? There's more people called butcher that end up being butchers and more people called Travis that live in Travis.

6:08And my mom and dad's names both start with a K. Oh, all right. Well, whatever. Oh, but they both start with a K. Well, that is very interesting. I mean, the idea that we can, we seek and we're always looking for people who might value us. So looking for overlap in any dimension is something we do naturally to form friendships. So are you saying that the same mechanism that we use to identify who our kin is in order to do reciprocal altruism, I need to look after them more than I would look after a cousin or a third cousin or a friend or a stranger, is the same one that does incest avoidance?

6:54So the system that is being used to identify kin for the purpose of being nice to them, like the inclusive fitness, is the same kin detection system that's operating for evaluating someone as a sexual partner. Wow, that's so cool. You don't think that's cool? I think it's super cool. I mean, it's economical, the idea that the brain computes one kinship estimate. Like I have an, for every person I meet, I have an estimate of what do I think the probability is? Not explicitly, not consciously, but by exposure to these cues, my brain has kind of ratcheted up or not ratcheted up this estimate that tells me and I use to determine how related or likely that person is to be relative.

7:43And that is an input into systems about how nice I should be to that person and how avoidant I should be of them sexually. Yeah, how close my heart should be and how far my genitals should be from this person. Okay, so this has to have been tested in adopted siblings. So if you see pregnancy or breastfeeding, but you don't share the early co-residence window, does that still trigger incest avoidance? How can you play around with some of the triggers here to see what really works? So my research focused on siblings. I did a little bit of the parent offspring as well, but the bulk of my research was on how do siblings figure out who they are, you know, who's related to them.

8:31And it looks as if there's two separate cues. So one unmistakable cue that someone is a close genetic or is a sibling is you see your mom, and to the extent you've met the right woman as mom, your mom, you know, pregnant, give birth to, caring for, breastfeeding a newborn. That is an unmistakable cue that that there kid, you know, breastfeeding from my mom, being cared for, you know, by my mom, is my sibling. and that actually operates regardless of actual genetic relatedness. So you can fake it, kind of. You wouldn't need to give birth to it. You would just have to breastfeed it. Right, and there's actually natural experiments that have shown this to be true.

9:15So in Taiwan, there was, that's no longer being practiced, but a form of marriage called minor marriage where parents would adopt in a newborn girl into their family, either because they had a son or they were hoping to have a son in the next year or so. And they brought up this adopted girl alongside their son until teenage years when someone said, and now you will marry. Oh, God. But they didn't realize that they'd triggered this incest avoidance mechanism. Correct. But one of the interesting findings is that the mom, the adopted mom would oftentimes breastfeed the newborn. And so what happened is, is that the son would have observed his mother breastfeeding a child that is in fact not an actual genetic sibling.

10:08I imagine that doesn't lay a particularly good foundation for a future successful marriage. No, but here's, so we're going, we're going to go a bit far field here, but the idea is Here's one of the striking things about that particular natural experiment that occurred. This was documented by anthropologist Arthur Wolfe. He found and reported that even among children who were raised together from very early age, many of them did marry and did produce offspring. So when cultural norms are that strong, it can actually cause you to do things that you otherwise might not choose to do. Now, in those marriages, those unions tended to end more often in divorce and there were more extramarital affairs.

10:57So the record keeping was incredible by the colonial government. But it was so those marriages, when they were raised together from birth, they tend to have fewer kids. but they did produce kids, more divorce and more extramarital affairs compared to marriages where it was the traditional arranged marriage, where kids were just raised in their natal household and then met as adults. Okay. So the first one is breastfeeding. So yeah. So sorry. So back, back. So the first really potent cue to who is a sibling is who did I see my mom caring for? Kind of this maternal investment. The second cue. So this is a great cue, but what happens if you're the younger sibling in a pair?

11:39You weren't around to see your mom care for your older sibling as a newborn. What are you to do? And so this starts to get into the Westermark effect. So Edward Westermark was a Finnish social scientist, and he recognized that children who were raised together throughout childhood tend to develop a sexual aversion toward one another later in adulthood. This has been termed the Westermark effect. And what he was identifying is this second cue of co-residence duration. So it's been operationalized as co-residence, meaning that if you're the younger sibling in a pair, you've got an older sibling, how do you know that they're actually a genetic relative?

12:19How does your brain figure that out? You track how long that they lived with you under the same roof, receiving care from the same two individuals. So it's really still about parental investment, shared parental investment, the amount of time that you see them being cared for by the same two individuals, predominantly probably mother, over the course of dependency. And so this is why the longer the duration of co-residence during early childhood, the more certain you are that an individual, again implicitly, is a genetic relative. And this leads to not only greater altruism towards that person, but also greater disgust about the thought of sex with that person.

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14:04When does the Westmark window start and stop? Is there actually a clear cutoff? So it was thought that perhaps there was a clear kind of imprinting period. My research shows that it basically, it just each year of co-residence seems to add a little bit of certainty or I should say reduces the uncertainty that someone is a genetic relative. So it looks like throughout the period of dependency, starting from birth, starting from birth is key. And so individuals who kind of meet later on, the effect still holds, but it's not as strong as people who are exposed to a sibling right from the get-go. I imagine the potential for an absentee father to come back into a daughter's life later in her life, this is one of the leapfrog avoided the Westermark window challenges that can cause some pretty uncomfortable outcomes.

15:02Well, it's so I would say that fathers don't recognize their daughters by the Westermark effect. So Westermark effect is going to be all about, yes, it's co-residence duration, and that might make it seem like it operates for all family members. But it's really about observing who is investing in whom, right? So the idea of if I have an older sibling, I see that the same female who's feeding me, yelling at me, caring for me when I'm sick and so forth is also doing the same thing to another older child. I have a good idea that that's my sibling. And the longer they require that type of investment, that's the kind of period of co-residence that we're talking about for FOP.

15:44But you raise really important things. So people who are not exposed to these cues. So what does this mean? So this gets us into fun territory. So people who are not exposed to these cues, they really don't map other people on as siblings. And so fast forward to modern environments where you now have these sperm bags, right? So you can have guys who are depositing their sperm and women are collecting it and they're having all these kids. And now there's all these half siblings running around. And now you can meet them. In fact, I remember, I don't know, 10 years ago, but it was probably more like 20 at this point, that there was a show that kind of brought together all of these paternal half-siblings.

16:26And they all, they were really enjoying each other's company. And I think there was one remark about even being attracted to one another. And so you wonder, how does this happen? Well, a couple of things. There's a couple of things going on. First, there's no natural sexual aversion that's developed. There's no system that's activated to say, this is my sibling. You telling me that you're my sibling, that a person is my sibling, that's not really going to do very much to me, that explicit information. It's like someone, imagine someone knocking on your door and saying, you know, your mate that you've been living with for 15 years, that's really your genetic relative.

17:07And so it really wouldn't really change the way you feel. You might say, well, maybe we shouldn't have more kids. But in general, it's not going to kind of cause a disgust, I would guess. But here's the other thing that's interesting. By virtue of sharing, why is it you find like what's called genetic sexual attraction? So it's been thought to be a thing. Have you heard of this genetic sexual attraction? That's good. Maybe it's not out there. Maybe I shouldn't talk about it. Get it out there. Information hazard. We need to share it. I'll put it out there and I'll just kind of wipe it away. So genetic sexual attraction.

17:41It's been thought that, oh, we actually really are attracted to our family members. So Freud was right and we kind of harbor these sexual desires. No, not so much. And so I would say probably what happens is that by virtue of the fact that we share genes in common with our close genetic relatives, we develop very similar preferences. right so imagine designing your perfect mate right so what is what does your mate look like what do they like to do what do they like to eat when do they like to get up when they like to exercise what kind of you know all these kinds of things you know it's like you and then you finally meet someone it's like you like kung fu movies i like kung fu movies you like spicy foods i like spicy foods you like getting up really early in the morning yeah you like reading and You're like evolutionary psychology.

18:32I mean, literally, it is you imagine all these different traits that line up in your really good friends and the mate that you would design if you could. Suddenly you meet a sibling. who actually shares a lot of these preferences and these dispositions. And it's like, well, this kind of hits a bullseye. And so the fact that, you know, people might find genetic relatives without a sexual aversion present, people that they enjoy spending time with doesn't surprise me. Well, I mean, I guess it depends how annoying your brother or sister is, but a lot of people, a lot of people like to spend time with their brothers and sisters, not just because of the history that they've got together.

19:13And if you remove the incest aversion, if you remove the disgust response and you're of the sex that that person is attracted to, it's like, well, why wouldn't you? Why wouldn't you do this? And what you're saying is basically, if you weren't brother and sister, but you are, but if you weren't, what would that be like? It'd be pretty sweet because you know 50 percent of everything we are psychologically is at least in some part shaped by our behavioral genetics okay well i mean 50 percent is a lot more than a lot of relationships that have lasted for quite a while i'm not quite sure what to say in response to that but what you did so i'll just say okay and this other thing is that what you bring up though is Jonathan Haidt's great experiment.

20:04Are you familiar with the Mark and Julie experiment? Maybe. And moral dumbfounding. Okay. So Jonathan Haidt did a really great study on moral dumbfounding that had to do with inbreeding avoidance. And he brought students into the lab and, or participants into the lab, and he gave them the following scenario. Imagine there's Julie and Mark and they're brothers and sisters, they're brother and sister, and they decide they want to have sex. And they decide, you know, they really want to. They're adults. They're consenting. They're going to use like five condoms. They can't get pregnant. No one's going to know.

20:41They're never going to do it again. You wipe their memory and they'll never even remember it. And no one's going to experience any emotional or physical harm. It's something you really want. So it's all positive, all, you know, win-win. And so, you know, and so Jonathan Haidt would pose these questions to participants and say, is it wrong for them to have sex? And, you know, all the participants are like, yes. And then he's like, well, why? Well, the condom could break. No, no, no. Condom doesn't break. They're wearing five of them and she's on birth control. Like everything's fine. Someone could find out.

21:15No, no, no. And so, you know, they try to kind of find a way and a rationalization as to why it's wrong. And finally, they just give up. I don't know. It's just wrong. And so he called this moral dumbfounding. And it's really a good question as to what's going on. And are people saying that it's wrong because they're concerned about the harm that could befall Julie and Mark? And most people are saying yes, because most people still think that there could be a harm. I actually think that the reason why people say that it's wrong is not because of Julie and Mark. I don't think people care about Julie and Mark.

21:53I think that people care about being in that room with Jonathan Haidt and the other experimenters to be like, I think incest is okay. I think it's okay. Oh, so you think it's all just like observer effect stuff? I think it's the idea that I could be going against a societal norm that the majority is on the other side, and I could be seen as a minority. I think we're very, I think we are very sensitive to sticking our necks out on issues where a majority holds one and we are going to oppose it publicly. Well, I mean, surely you could just control this by changing the way that people submit their answers, right?

22:29You could submit them in complete anonymity. You could do it through a form. You could do it anonymously on the internet. If this is such an obvious potential explanation, this has to have been tested. I don't think it's obvious because I think people have been so focused as morality is cooperation. And I think that morality, I mean, you wanted to talk about this and getting back into the disgust and morality stuff, but it's very possible that people are very sensitive about moral condemnation. And anyway, I think you only get to this hypothesis if you think that people don't care about harm to them, but harm to themselves.

23:08okay what what was that study where you asked men to imagine tongue kissing their sister um that was uh well there's been a few

23:22i've done other stuff like on positive things like gratitude no no no sorry i'm keeping my foot on the neck of incest at the moment incest avoidance please um okay so yes there i've done a few studies. So one of the ways that we have to collect data on what people find objectionable and disgusting is to ask them to imagine engaging in a variety of sexual behaviors. And so how do you do this? And ethically, right? So asking subjects to imagine tongue-kissing their sibling or having sex or, you know, taking a shower with them. What's interesting about that is at least a while back when I collected those data, females were all at ceiling.

24:10You couldn't like one to seven, they'd be like 10. Like you wouldn't, they wouldn't be happy. The amount of variation that I found in female responses, seriously, that the bars on my graph were like, oh, basically touching. There were very, very little variation, all squeezed right up at ceiling. Um, males, on the other hand, uh, the variance structure was, uh, quite wide, which I found, um, humorous, but it all gets back to, I mean, it's not humorous. This is a very serious subject. It actually, it is. Um, and so it gets back to some of the costs of reproduction. Females, when selecting a mate, have to consider all of, I mean, they are on the hook for, nine months of, 10 months of gestation, three years of lactation.

24:56And so getting a baby up and running is easily three, four years ancestrally. So any bad decision in terms of investing time and energy into an offspring with a reduced chance of survival would have been heavily selected against. Males, the opportunity costs are far less. And so males, while they should not be pro-sibling incest, would find it slightly less horrifically objectionable as compared to females. Women also usually have a lower disgust threshold than men, right? For most things, yes. For most things. You know, I tested this. I asked women a whole bunch of different things about how disgusting you find a variety of things.

25:39And you're absolutely right that women are far more disgusted by a great many things. It ends up there are a couple things that flipped, which were, you know, changing diapers, females are like, and then having sex during your period. So that also, sorry, it's gross. It's all gross. But so there you go. So women are disgusting just specifically in specific situations. I think just the word period or tampon grosses guys out a little bit more than women. I think that's probably. Great, we're way less familiar with it. A quick aside, if your sleep's been off, you're taking ages to fall asleep, waking up at random times, feeling groggy in the morning, Momentus's Sleep Packs are here to help.

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27:28Like I understand logically why it's a terrible idea, but I don't get the same gut level recoil. Do you know it's like it's like hearing smokers say i need a cigarette like i get the concept but i don't have the the craving or whatever or the opposite of the craving like i don't have that that aversion um why well i mean is that normal have you looked at at people who it is literally like i don't have a language i guess someone could say well imagine having sex with your mom and i'm like yeah like that you've got the age thing that's already in there on top of like the fact that she's my mom. So I think for most people that have siblings, it's almost like they have a language of disgust that I don't have the understanding of.

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28:12Does that make sense? Oh, a hundred percent. So I'll tell you about another study that I did that didn't get published, but it's enjoyable nonetheless. And so I don't have a brother and my co-authors don't have opposite sex siblings. So Lita Cosmides is an only child and John, John to be only had brothers. And so the three of us sitting around talking about how to gross each other out with these acts, it was actually, it was very disturbing talking about these things with your advisors. I have a, I remember that conversation and being like, I'm, I'm done. I'm out. So, but it was, we did another study, which was videotaping facial expressions.

28:58At the time I started kin detection, no one had really started to look into the psychological aspects of it. But one of the things that we had to do was validate disgust as a possible measure. And in science, even though it's obvious, if you just ask what emotion comes to mind, If you think about tongue kissing a sibling, most people, it's really gross. And there you have your dependent measure. You have to establish that. So I set up a lab where I recorded people's facial expressions and did a variety of things to understand what facial, what muscles were actually activated in response to a variety of different acts.

29:38Things that we know elicited, discussed, but then also the sibling incest stuff. and um so there people are looking at the screen seeing acts come up on the screen and and just responding to them or just reacting to them and most of them would have these you know so in addition to like eating your favorite dessert it would be like you know putting your hand in a toilet and all these other things that you would see the muscles the nose scruncher muscle for disgust activate when i was matching what was on the screen to participants because those are two different video feeds. I remember seeing one of the matching up the seeing a guy kind of smile like, hmm.

30:18And I was like, wait a minute, do I have the time, SMPTE time code right? Like, am I matching it right? Because it says like tongue kiss a sibling. Like, what's going on here? I was like, oh, no. And so I was like, and I remember furiously going through all the survey pages to be like, please don't have a sibling. Please don't have a sibling. And it ends up the guy didn't have any sisters at all. And so I found that really interesting. It kind of gets to what you're talking about, the idea that it doesn't map onto anything. And so it was like, imagine, it was basically like, imagine having sex with a girl.

30:49And he's like, hmm. And so without that natural aversion, you don't have such a strong reaction. Right. right okay next topic yeah if incest disgust is so strong why is incest porn such a huge category online you'd expect it to barely exist and yet it's massive well i mean are they really siblings i mean people do anything for money well i mean first off it's money and so the idea is if people are going to pay and you need money. I mean, that's sure. People do stuff for money and people do gross stuff all the time. No, no, no, no, no, no, no, no. Why is there an audience for it? Oh, why is there an audience for it?

31:41Because why are people doing it? I don't think that that many brothers and sisters are being employed. That would be, that would be a very special kind of relationship. It would be a really special kind of business. Yeah. I imagine that the margins would be really bad. The amount of money you'd need to pay most people to have sex with their sibling would probably be pretty high.

32:06Yes. Why is there a big audience for it? Why is there a big audience for it? Well, I watched Game of Thrones and the idea that, you know, these two people, what is it? Jon Snow and, you know, Daenerys, they were, ended up being related. I don't think that prevented people from watching that. I think people aren't, It's just two people who are naked having sex. And not only that, so there's that. And then the idea of kin detection is imperfect, right? So if you don't have a sibling and you're like, oh, well, this sounds kind of neat and risque. Oh, right. Are you saying that incest porn is exclusively watched by only children?

32:50I don't think it. I don't, I don't, my hypothesis would be that a guy with six sisters is not the person who's watching this. That would be so, that would be such a fucking good study. You should do this. This is your next study. Your next study is to work out, is to work out, um, whether the likelihood of watching incest porn goes down based on the number of opposite sex siblings that you've got. Yes. The world needs to know. Okay. Well, I'm, I'm really hoping someone in your audience will now undertake that. This is you. This is you. You're in my audience. What else are you doing? I'm writing a textbook.

33:29I'm starting a business. Come on, man. I'm busy. Well, this can be another, you know, there's more stuff to do. Anyway, I think you're right. I think people don't, it's not like in order to watch this incest porn, you need to observe these two people grow up in the same household as you for the first 10 years of your life and then watch it and then see it. because the fantasy, I guess, is a... I wonder whether it's a little bit of like contravening, you know, in the kind of the same way that dominatrix stuff or being insulted or whatever. It's like, ooh, this is a social norm. And by breaking it, this is cheeky, but it's done in a safe way because you don't actually have the disgust response.

34:08I mean, they're not your siblings. That's true. Yeah, this is whatever the thingy and Julie. The Mark and Julie, yeah. Mark and Julie. It's Mark and Julie all being watched. All right. Ayla, who I think you'll probably be aware of, she ran a poll and said, if your very attractive cousin wanted to sleep with you, would you? And there was 12 ,000 votes and it was almost exactly 50-50. Now, I will say her audience is perhaps non-typical, like rationalist, sex positive, slightly autistic coded. But that number still surprises me a little. It doesn't surprise me. Well, first off, cousins. Hot cousin?

34:4850-50? Cousin marriage is still, I think, one of the more prevalent forms of marriage worldwide. And so as soon as you start to drop off of nuclear family members, the biological, deleterious, and harmful effects of mating with close relatives drops off pretty fast. What's the comparison to parent, to sibling, to cousin? I mean, it really it drops off really fast. So within the nuclear family are the greatest risks, right? So you have parent offspring, certainly mother, child, there's greater certainty. But, you know, degree of relatedness is, you know, 0.5. Siblings tend to be on average 0.5.

35:30But as soon as you go to cousins, you get to an eighth. You go from a half to an eighth. And so that's on average. So I would say, especially when there are norms kind of pushing all of that and you didn't live with them. And so your kinship structure is more, your aversions aren't as strong as they would be to nuclear family members for good reason. Would you have, is there such a thing as you observing the baby of your mother's sister growing up in the same household as you, being close to them, knowing that it's not been raised by your mother, but knowing that your mother and that woman are close and that woman raised that, is there such a thing as being able to tune up the cousin aversion?

36:16Yeah, I bet you there is. I mean, just like there's an ability to tune up the sibling aversion by having someone come into the house and be raised by, you know, an adopted child and so forth. And so it's, I suspect that there's a lot more research that needs to be done on this. And now that we have these amazing ways to collect massive amounts of data, it'd be very interesting. You asked about a kind of imprinting period or developmental period, a sensitive period. And the answer is, you know, we don't exactly know. I mean, there could be. My data, I collected data from like a couple hundred people.

36:56And so the bins that I have, like I have most people 3 to 18, they lived with their siblings, some 4 to 18, 5 to 18. But imagine having the ability for every bin between 0 and 18, filling that with 10 ,000 people to kind of understand patterns. And so that would be a really great study to answer the question definitively. I agree okay uh you had this fantastic article on crying which I read a few months ago it's it is one of the best things that I've read in a long time I think it's really really great so I want to we've talked about incest now I can talk about crying um before we continue I've been drinking AG1 every day for years now because it's the simplest way that I found to cover my bases and not overthink nutrition.

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38:18Plus, if I ever actually found something better, I would switch, but I haven't, which is why I still use it every day. And if you're on the fence, they've got a 90-day money-back guarantee. Buy it and try it. And if you don't love it, they will give you your money back. Right now, you can get a free bottle of vitamin D3K2, free AG1 travel packs, a welcome kit, and that 90-day money-back guarantee by going to the link in the description below or heading to drinkag1.com slash modern wisdom. That's drinkag1.com slash modern wisdom. What's the evolutionary story behind crying? Why would leaking water from your face ever be adaptive?

38:56It is. Well, okay. So before we get into this, I just have to say for the record, because it's an important record. We've talked about disgust, but I've also done a lot of work on gratitude and other emotions. And so, but it's my work on gratitude that got me into tears because gratitude, um, and so see how I'm, I'm kind of changing, but gratitude, it's an important emotion that's responsible for jumpstarting friendships. Uh, it is an emotion that identifies when other people value you, right? So someone does something, uh, that you perceive to be a benefit, you say, thank you. You are basically saying, you know, I, I, I value you for having done that act.

39:37And, um, it would be great if you continue to do that act, uh, with the promise that potentially we can form a cooperative relationship downstream, but it all hinges on what we call kind of social value in the, in the article, it's called welfare trade-off ratio, but let's not talk about that. It's really just about how I value you, how I perceive you to value me. And so, because when we're strangers, I don't think you will value me or I don't value you. And then use something nice. It's like, oh, how do I recognize? How do I positively reinforce that beneficial behavior, that positive behavior?

40:14And gratitude seems to be the way that I say, hey, that was really great. Keep doing that. Like, thanks so much. And so, but it all hinges on these internal assessments of value. So how do we get people to value us? If you are, I promise this is going right straight to tears. And so if I am big and strong and formidable, I can just get you to be nice to me, right? Under threat of penalty. Like I can impose costs. I can beat you up. I can have other people beat you up. I have money. I can do all sorts of things. And so if I, I can use anger as one device and strategy in order to get you to value me.

40:55I can also use gratitude. We've talked about this in the literature as prestige and dominance, but I think it tracks a little deeper than that in terms of the strategies of how to get other people to value you. But here's the thing. If I'm on the other side, if I am low leveraged, if I'm in a situation in a relationship where someone's imposing costs on me or threatening me, what do I bring to the table? How do I negotiate? You know, what's in my arsenal? And so I could either just kind of give in and be exploited and manipulated all the way to the end. Or I can try and kind of express that you are imposing too much of a cost.

41:35You are asking me to deliver too high a benefit to you. That's going to start digging into my own interests. And TEARS is one way that we use to communicate costs or better yet, the intensity of a particular state. So tears, I'm mapping it more onto sadness. It's not necessarily just associated with sadness, but using sadness as an example, the idea that my tears communicate to you, you are starting to impose a cost on me that is threatening your value in this relationship as well. It might be worth your while to stop. And so it's a way it's the it's a tool used by the lower leveraged to get other people to stop imposing costs or to start restart the delivery of benefits.

42:28So kids cry, throw tantrums saying, you know, you're not feeding me enough or you're not feeding me the right things, you know, because they're not big and burly and they can't be like, you're going to make me that hot dog. They're just going to cry. I don't want mac and cheese. so um but they're so tears can communicate quite a bit more generally they communicate value and so we associate them a lot with the negative value things that cost us but they can very much be associated with the positive side too it's indicating the kinds of things that i benefit you know that i find quite beneficial so you know someone delivers an a hugely unexpected gift to you.

43:09You could be moved to tears. Someone does something and donates a kidney or does something life-saving. The idea that you could be moved to tears by such behaviors, it's showing and illustrating high value. So it's very much like the scream, but it's used by the lower leveraged in an interaction. What does lower leveraged mean? Means the person who is less likely to get their way in an interaction. So it could be the less physically formidable, the lower socioeconomic status, the less attractive, the smaller. Wow. Okay. Okay. I get it. So women cry more than men. Kids cry more than adults. Have you looked at trying to control this stuff?

44:00So for instance, let's say that you had a woman in a relationship, but she was socioeconomically more successful than her partner. She was the primary breadwinner. Or you had a mate value discrepancy where the woman was higher mate value, more famous, more statusful, you know, trying to rebalance these scales. Do we tend to see that change? I would say you probably absolutely do. Wow. Wow. And then and but there's always the fun crocodile tears. Right. So those are the fun ones where it is people who use tears because they know what they do. And so, you know, psychopaths, dark triad people will pull out crocodile tears in order to get you to think that they care.

44:48And so that's always an interesting feature. But there's a you can tell. I came up with one way to tell. This has not been studied, or at least I don't think that this has been studied and I'd love to study this. So if you've ever cried. Like if you're like me, even in a movie, a dark movie theater, if I like start crying, I like I like to start to stare. So it's like dry up, dry up. Don't let anyone see you crying. You know, it's like you kind of like you hide and you don't want anyone to see you. You don't want anyone to see you. It's kind of like I don't want to be perceived as weak or low leveraged or someone who you can now take advantage of and exploit or anything like that.

45:25Right. So I don't I don't want to have lost any ground in any type of leverage, you know, in any relationship. Again, it's not explicit, but it's just like we tend to hide these things. But people who are trying to use their tears for more manipulative purposes will cry and be like, don't you see my tears? These are tears because I care. And so I think people who use crocodile tears need them to be on display. Oh, that's so great. Yeah. Allow me to put a billboard up so that my tears can run down the front of it. But isn't it strange that people who are crying and they've got, you know, if this theory holds true and at least a good bit of the time, I think it does.

46:06People are, I'm trying to tell you, I value you or the thing that you just did, or you were imposing costs on me and I would really like you to stop. I need you to see this, but also I'm ashamed of the fact that my body and my face and my eyes and the water has betrayed me. So I'm going to hide, but I'm going to show you, but I'm going to hide. There's a tension going on here. There is. I'm not giving up too much ground in this relationship, but just for this one instance, you should know that you've gone too far. So an interesting thing is that what has been studied are tears and anger at the same time because women tend to, when they get angry, also tend to tear up.

46:54So if you are in a situation where you're out leveraged, so you're in a group situation and you're not being valued and people are pissing you off. Right. And so and you say something right. You're angry. You're like if you had, you know, if you had muscle behind you, you'd be in good shape. But if you find that you're the only one making a case for something, what so women in these situations, they tend to get angry, but also tear up. It's like, but again, it's that tension. It's like, if I could, I would, but I can't. So I won't.

47:34Yeah, that's so great. And I don't think, I haven't seen guys get, do the angry cry thing in quite the same way. Their rage is able to sort of burst through it a little bit more. I think in most situations, yeah, no, I don't think that's a tactic for males who don't. So listen, I mean, there is a big difference in, there are huge sex differences when it comes to formidability. Walking around the world where, you know, around in modern times, I mean, I love modern times. Like I can walk around without really under threat of being like, you know, hurt. And so, but that's relatively recent in human evolutionary history.

48:16Like there were, you know, you go somewhere foreign and suddenly you realize like, maybe I shouldn't be walking around alone. Like this is, I'm going to hire someone, you know, tomorrow. And so the idea that females are less formidable and they are at risk of being, you know, I mean, you walk around and it's, here's what I was told. I don't know if this is true. Tell me if this is true. That when guys go into a room, a new room, new people at a party, wherever it is, a bar, the first thing they do or one of the things they do naturally is they kind of sweep the room, like who else is there? What other guys are there?

48:50And kind of take a kind of back of the nap and calculation about who's bigger, who's more formidable. Like, who can I take? Who's dangerous who should i be wary of and who don't have to worry about kind of thing is that is that something men do when they walk in a room uh i i don't know whether it's that conscious but i don't think it's conscious uh there's certainly stuff that happens that's kind of interesting like um if you're in a room this is a cool way to look at it if it's a mostly guys room ideally in all guys rooms as soon as you throw women in the mix it becomes messy um but if you've got a table um you'll see what is the angle of the chair, what are the angles of the chairs mostly pointed toward, and you will see that there is a head of the table, even if there isn't a head of the table.

49:35Another way that this happens is when somebody starts speaking, when a guy starts speaking in a room, what is the likelihood that some or all people shut up? I've been in rooms with some guys, real, real status quo guys, that if they fart, everyone will decide to be quiet. And you can really tell an awful lot about where the hierarchy falls by who's nearby, proximity to that person, whether they will keep talking, whether they're happy, whether they look regulated or whether they sort of seem a bit more sycophantic, appeasing. So it's all that. I mean, that's actually me getting a little bit feminine, I suppose, with it, as opposed to the more like brusque shoulders back type way.

50:21That's more like status game playing like relational stuff. But there's still even the formidability, I think will play a big part of that too. I think if you've got some big fucking dude in the room and he starts speaking, I think your, let's say, formidability status and resource cues, something like that, like how big are you? Who are you? And what do you have? Something like that. If you had these buckets and there is this invisible score that is above everybody's head, which is some sort of aggregate of all of those things put together. So like the really formidable guy who nobody really knows that much and the really statusful guy who might not be quite so formidable, that would be an interesting, but like, who do we, oh, well, actually I'm physically a little bit weaker.

51:04So maybe I'll be more scared of the formidable guy, but statusfully I'm a little bit stronger. So I don't mind the, you know what I mean? Like how, where am I in the pecking order? All of that is done in a, not very long when you sit down in a room, I imagine at the back of my mind. Yeah, no, I think that stuff, I think the nonverbal behavior is really interesting. Someone that I've read and listened to in terms of the podcast is Joe Navarro, who's done a lot of this work on nonverbals. And so it's fascinating stuff if you haven't had him on. Yeah, he's great. In other news, you've probably heard me talk about Element before, and that's because I am, frankly, dependent on it.

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52:48That's drinklmnt.com slash modern wisdom. So if tears are telling another person, I value this thing or you're imposing costs on me and I would like it to stop, why do we cry when we're on our own? oh because i think that we have dramas played out in our head all the time you know like we very easy to imagine a whole bunch of stuff typically it's not just you know nothing sparks us usually there's a thought or some type of sequence but who are we crying to oh i think it's simulating i think there's simulations all the time it's just like you know haven't you ever you know you know laughed like i i work you know in my place on my own and if anyone were ever to watch, like they'd be like, she's crazy because she's laughing all the time just by thinking about some of these things, you know, it's hard not to chuckle.

53:41And so, but what's that all about? It's like me thinking about stuff, you know? And so I think that when we think about things, we can absolutely simulate what would be my reaction in this particular situation. So that kind of playing with possible events that could play out to be prepared for them and so forth. Okay. I think most people and me too I think that sounds a bit surprising because not that it's not true but I'm like I'm not gaming this out like I don't want to be fucking in a ball of tears on the floor at the moment having just watched this dog come home to or this this soldier come home to his dog after you know three years away and now the dog faints and now the daughter's there and you know but I'm not I'm And is it, am I confusing the fact that I've seen that those people are here with me?

54:34Is it the fact that my whatever system, crying system, is unable to detect the fact that that's virtual or not? Is it the fact that it's unable to detect the mental imaging that we've given versus a real situation? Is it the fact that our mental situations are just so powerful that it doesn't matter if there's other people around that we experience them as if it was happening in front of us? I think I think you have empathy with score one for not being a psychopath. I wish I cried less. I wish I wish I was less of a pussy. My crying threshold is, you know, the discourse threshold thing we said before, my crying threshold is embarrassingly low.

55:12It fucking blows. That's our listen. Empathy is not overrated. And so I would say, you know, I think that first off TV and story, we evolved with storytelling. We evolved with people in front of us telling stories about people and about, you know, you know, our ancestors and so forth. But I think that when we see them on TV, it's a little confusing to our ancestral brains, that's for sure. And so, but hearing about these things and putting yourself in a situation and simulating, I think is, or being, you know, showing empathy and putting yourself in the shoes of other people and what you would experience.

55:48Because there are people who don't have that ability, right? So you have people who, you know, psychopaths, for instance, who do not have a capacity for empathy and would not cry. What about when grief? Because let's say somebody's passed away, who are you crying to? They're gone. What are the tears for? Well, I think you're showing other people your need state. That's one thing. But I think a lot lot of things are going on at that point in time. So being upset and depressed and grieving the idea that it's a loss. And typically we would have been around, I mean, there's no such thing as privacy to, you know, a hunter gatherer.

56:37So, you know, something happens and you would have been around other people and kind of this automatic response of I am in a need state would have potentially been quite beneficial. I, you know, I haven't done, so I, a lot of this is speculation. So the, so just to stay on, you know, terra firma here, I, the paper really was about, I was very curious researchers who had been studying tears showing that you show subjects faces displaying various emotions. And if you add tears to some of those emotions, they're easier to recognize. And when I was, so I'm the editor of the Fields Journal, Evolution and Human Behavior.

57:22And so I had one of these papers in front of me and it struck me like there's a lot of research on tears that it hasn't been hooked up with the cognitive side of things, what's going on internally and what this signal value is. And it had struck me that no one really thought about is tiering an adaptation, like what's going on here. And so thinking about when we tier and what might be going on, it seemed to be very much tied to social value, right? So being around people who value us and we are going to try to get them to stop imposing costs or try to elicit more benefits from them. Obviously, I talk science speak, but that's not consciously available to us.

58:02We just cry and it has the effects that it does on the people around us. Okay. So

58:11positive events, the reason that we cry at positive events is like, this is good, do more of it. Like an encouraging thing. This is a value to me and I wouldn't do this ridiculous thing if it wasn't? Yeah. Reliable signal of receptiveness? Yeah. You're marking this is of high value to be. I perceive the events and what's going on now to be registering in my brain as high value. Okay. Why not make our whole body shake? Why not raise our hand in the air and wave it? why because crying presumably wasn't crying is here to lubricate our eyes that's why crying that's why the tear ducts exist primarily why has our emotional system repurposed that why don't we shit ourselves like why don't we why don't we just yell like why well maybe you do i I don't know.

59:13Why tears? What is it about the water coming out of the face that is particularly useful for this? It's front and center. And so it is something that is readily available. It's a really good question. And so this was obviously one of the main questions that our reviewers had is like this. Why this? Why now? And so one possibility is that it was built off of. so if you have an onion and you hold it close to your eyes and the acids kind of interact and you start to tear um and so the idea is that this is a negative a negative stimulus so it's already kind of being associated with there's something negative in the environment um that is affecting me and so that very much could have been the bootstrapping way that another more negative stuff uh could then have been registered by other people so to the extent that i mean to the extent that that was possible.

1:00:06That would have been one possible lineage for how this came online. Okay. I seem to - You buying that? To a degree. To a degree, I do. I don't - The answer is I don't know. But the face does - Another part of it is, okay, yeah, front and center, right? Here it is.

1:00:31It's very hard people, I think it would take a bit of, even me with my wimpy cry threshold, it takes a bit of work for me to get it going. So usually for most people, apart from the psychopaths, a pretty reliable signal of authenticity. So it's not cheap. It's not that cheap. Another thing has to be, you really need your eyes. Like you really, really need your eyes to see. And if you choose to have water pour out of them, you have temporarily incapacitated yourself. And if you, again, another sort of reliability. A costly signal. Add on. Yeah, yeah, yeah, yeah, yeah. Yeah, yeah, that all makes good sense.

1:01:16I think, I mean, look, this paper was just written. It kind of throws out a whole bunch of ideas. And now it's time to say, put it through its paces, test it and, you know, see where it goes. I think that, you know, on the positive emotion and negative emotions. So things like gratitude, but also depression and sadness and pain. I think that there's a lot, there's a lot of work to be done. That's a good point. Why do people cry during, I remember the last time I cried due to pain, physical pain. And I was, I think 13, and it was one of my first adult cricket matches. I don't cry due to pain anymore.

1:01:58physical pain. I don't think that there is an amount of physical pain that I would be put in. It would have to get toward the emotional pain. It would have to be an emotional element of this. Is it just that as you grow up from child to adult, you are able to better understand your capacity to deal with pain and the fact that it doesn't necessarily have an emotional component to it? Why is it that kids cry when they bruise their knee, but I don't? um i mean i i still cry when i hurt myself like i mean i i think yes and i don't tell anyone um and so uh it's a really good question listen as a kid i think the idea that i i need help you know like help me i'm in pain and this and or you know stop this stop this un unattach this bristle do something like there i think there that it definitely is a signal i'm trying to actually think about it now like because you know i've cut myself with a knife and have i cried i think i've cursed more than i've cried um and that's strange and it's strange because it's not you know but i guess look the same or similar stimulus can cause different responses some breakups may cause somebody to shout and scream in someone's face because the the specifics the the the flavor of that one was cantankerous.

1:03:21It was aggressive. It was adversarial. And then another may be loving and, and, and painful and, um, uh, you know, like, um, melancholy. And those two would have very different responses in one, somebody may not cry and in another, they may. So I want to throw, I want to give you a harebrained idea that I had, and I, I don't think it's going to pay out, but here's what I was thinking. So, you know, after a breakup and you just, you cry and like you cry uncontrollably. And I was thinking, so while I was crying, I was like, why am I crying? This is like, I got to stop crying. This is like, I want to stop crying.

1:04:04Like this is done. Let's be done with this. And so, but then I was wondering the function of it, Is it like a data dump in the sense of someone that you held such high value for and then you realize and you simulate and you realize they don't value you anymore and that cost and that kind of ratcheting down of someone valuing you? Right. Because you have to literally have that time to have that realization that they do not care about you at all. Right. So and so but the idea that potentially crying might be a way that, you know, it just it's a it's a so, yes, our social value is ratcheting down, but might that it's all chemically mediated.

1:04:49So the question is, are you also ridding yourself of that? So I was if I had like a well-funded lab, you know, I would think like if you could possibly capture people's tears as they are going through a breakup to see whether or not, you know, the pre the pre kind of level of, I don't know, oxytocin, whatever it is that kind of governs social value and attachment and closeness. but is it kind of being dumped out through the tears to kind of help kind of re-establish? So good. I think that's great. I think that's really cool. I think that's really cool. And I think that someone needs to give you a million dollars so you can go and do it.

1:05:27Um, what it makes me think about is how much of crying is about changing other people's behavior and how much is about recalibrating our own emotional state. I think there could be multiple things going on. I think there's probably because I think that just like shouting can be done in most emotional states, like different types of shouting could be used to help express anger as in joy or gratitude or shame. Like, you know, you find that the volume and amplitude of our voice can definitely do that. So why? And those are different types of emotions. Some are internal calibrating. And some of them are other calibrating.

1:06:10So my anger and gratitude is to calibrate you. But my shame and my pride is calibrating me potentially. So in any case, I think that you just put your finger on a really interesting thing that there's probably multiple things going on. So cool. So cool. Deb Lieberman, ladies and gentlemen, you're fantastic. sake you're part of this weird like council mason masonic like group of cool keep going doing evolutionary psychology and everybody needs to follow you and uh i think your works i think your works wonderful and um i enjoyed speaking with you at hbess and uh i think that you need to keep doing more stuff so why should people go if they want to check out all of your fun cool work about incest?

1:06:59Well, actually, on the Center for Evolutionary Psychology is a whole list of a great set of papers, not only on kinship, inbreeding avoidance, altruism, but also morality and anger and cooperation and coalitional psychology. So Center for Evolutionary Psychology is where I would direct everyone. And also, you can read about it in the textbook that is hopefully forthcoming at the end of 26, beginning of 27. And if you will permit me just to say one thing as an academic, and the frustration that I often hear a lot of people who want to get access to these things is that they're hit with these paywalls.

1:07:39And so my business venture with a partner, the problem we're solving is allowing people to get access to articles, not only news, but journal articles that are currently held behind paywalls for subscription, but allowing people to get just the one article they want when they want it. So that's what I'm up to. When's that available? Can I get that now? Check an app store soon. Media Byte. We are on it. Okay. When do you think it'll be launched? When it'll be launched? Hopefully late 26. Okay. Well, hurry up because I need that. Deb, you're great. Keep doing your thing. Thank you. You too. Be well.

1:08:15This is great. I get asked all the time for book suggestions. People want to get into reading fiction or nonfiction or real life stories. And that's why I made a list of 100 of the most interesting and impactful books that I've ever read. These are the most life changing reads that I've ever found. And there's descriptions about why I like them and links to go and buy them. And it's completely free. And you can get it right now by going to chriswillx.com slash books. That's chriswillx.com slash books

From the publisher

Dr. Debra Lieberman is an evolutionary psychologist, professor, and researcher.

Why don’t we feel sexual attraction toward our siblings or close family? Evolution seems to have hard-wired the brain to prevent inbreeding, a pattern shared with many other animals. So how does this mechanism work, and what are the moral or ethical arguments surrounding incest?

Expect to learn why evolution has designed you to not want sex with your sister, how animals actually detect who their relatives are, what the high level explanation is for why humans don’t want sex with their kin, the moral argument if it is okay if two adult siblings had consensual sex, how big the actual genetic risk is for first cousins, what crying adn tears actually communicate from an evolutionary perspective and much more…

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