AS266: Was Richard Carrier Wrong About Evo Psych?

Transcript

This transcript was generated automatically and may contain errors — the audio is the record.

0:00:29 Thomas: Hello, and welcome to Atheistically Speaking. This is episode 266, and I'm your host, Thomas Smith. Alright, before we get to part two with Lindsey on EvoPsych, very interesting topic, I just want to let my patrons know, and anyone who is thinking about becoming a patron at patreon.com slash atheist, that I've got a great bonus content with Eli. Lie. It's going to be really, it's pretty funny. We had a really interesting, funny discussion and patrons will also get early access to a special announcement being made. Uh, and, and that's all say, but, uh, so patrons get it early. That'll be out sometime this week. And so if you want to check that out, please feel free to check out the Patreon. All right, here is part two with Lindsey.

0:01:27 Lindsey: There was a general theme that came up about the fact that we aren't testing theories, right, that our methods don't lend themselves to actually testing theories. There's a couple of things to be said about this.

0:01:35 Thomas: That evo psych is not testing theories? Sure. Sure.

0:01:46 Lindsey: One is that, in hypothesis testing, or like when you're doing science, it's true to say that a study does not test a theory. That is actually true. But the way in which is true is not how it was being presented, I don't think. So a theory is like this broad general framework for synthesizing a bunch of different observations. So, like, evolutionary theory, for instance, right? That's like a very broad thing, right, a very broad set of principles that describes a whole lot of things. No individual study is directly testing evolutionary theory. Rather, we're deriving hypotheses and then, from that, predictions from this theory that then can be tested individually, and over a great number of tests, you can support a theory or fail to support it, right, so that, that's one point.

0:02:36 Thomas: But is is evo Psyc In a position that's maybe more difficult than other sciences where, I mean, when we have the, like, how much, I think one of the biggest criticisms is like, oh, evo sec is just a bunch of just so stories. And how do you test between them, you know, like between explanations, because you talk about that at all. Mm-hmm.

0:02:38 Lindsey: Yes. Oh. Yeah, absolutely. So that's true, and probably for those reasons that we talked about at the beginning, um, that it's, it's fairly easy to make up adaptive stories about different things that that is a true thing, but it's not equally easy to provide evidence for all of those stories. And so when we're coming up with hypotheses, what we are doing is not saying, well, we think this is why it's happening, and then just leaving it there. We're coming up with this hypothesis about what this hypothetical psychological adaptation might look like in terms of its structure and function. And then we're making specific predictions about the particular things that you should see characterizing the relationship between two things, given any number of constraints that you want to come up with. And those predictions are very specific and are falsifiable, and if they are falsified, then we say, look, we did not provide evidence that this is part of the specific adaptation that we hypothesized about.

0:03:07 Thomas: Sure. Are there any theories or or anything that come to mind that have been falsified through tests, studies, or tests, or whatever, in evo psych?

0:03:57 Lindsey: So. So there's, um, there's a highly, highly heated, or a controversial area of research on, um, evolutionary explanations of rape. You can see how why this would be a charged topic. Topic. But one hypothesis that was offered at one point was the disadvantaged male hypothesis. So the idea was that if you can't reproduce through female choice, then you should try to subvert that choice and rape. There has been absolutely no evidence presented for this hypothesis. So they've looked at whether, like, indices of mate value, for instance, predict likelihood of raping. They've looked at, like, actual success and to see if that predicts, you know, the likelihood of somebody becoming a rapist, but none of these predictions panned out and so this hypothesis has fallen out of favor. I know, right, so you're surprised because that sounded like a totally reasonable suggestion,

0:03:57 Thomas: Yeah. Yeah. Really? Right. Interesting.

0:04:55 Lindsey: Right? Yeah, but it didn't bear out. The evidence didn't support it. Yeah.

0:05:00 Thomas: So there are people still trying to hang on to it, or mentioned that it was very controversial, so it sounds that, that sounds like not terribly controversial, because, because if the evidence doesn't bear it out, then I guess it's not true. But are there?

0:05:02 Lindsey: Uh. Well, There's still, there's still research going on on the biological underpinnings of rape, and so the, the controversy is really over, like, whether you should be approaching rape from that position, right, and people are very uncomfortable with that. That's what's controversy about it, not necessarily that specific hypothesis. But just the

0:05:31 Thomas: Oh, OK. I see. Just the research at all. Just the idea that, yeah, OK, hmm.

0:05:33 Lindsey: Yeah. Yeah. People, people get very uncomfortable with that, probably because of, um, you know, the fact that that intuition that we talked about, that if you explain something biologically, it sounds like you're saying, well, it's natural, and so we should let everyone rape as much as they want, like, that, that's just not, that's not the implication, right?

0:05:56 Thomas: Right, obviously. And I would want to know, like, I would want to study psychopathy or something. I would wanna study, you know, even what makes people pedophiles or something It doesn't mean that it's OK. It just means maybe you'd be able to have some insights about helping those people or, or explaining it or whatever it is, you know?

0:05:56 Lindsey: Yeah. Right.

0:06:17 Thomas: Hmm. Yeah, that's, I don't really understand that pushback. That's kind of weird to me.

0:06:16 Lindsey: Exactly. Well, I mean, you do, though, right? It's

0:06:24 Thomas: No, I mean, I, yeah, I of course I understand you describe, yeah.

0:06:27 Lindsey: Like, I think that we kind of want to stay mad at bad behavior and and uh you know like like Sam Harris has talked about when you when you provide a clear explanation of why somebody did something bad the anger dissipates in a lot of cases and I think that people are uncomfortable with that, oh

0:06:31 Thomas: Yeah.

0:06:44 Thomas: Yeah I mean I, I totally understand that people are that way. I'm just saying I'm not. Like I don, yeah yeah

0:06:50 Lindsey: Right, yeah, no, it doesn't. I don't have that intuition anymore either, but but

0:06:55 Thomas: That's interesting. I mean I could, I could certainly imagine it being difficult if, if I or a family member were the victim of something. Like I could understand thinking like, I just can't get it out of my head that this person, you know, is responsible. And yeah, I understand that. But if the question is, in general, should we study this? It's like, well, yeah, of course, you Know, so interesting. Okay.

0:06:55 Lindsey: Yeah, sure. Agreed.

0:07:15 Lindsey: Absolutely. Agreed, and also, so, um, this is relevant to to testing as well. Like, he, he talked about kin, kin selection and homosexuality, and the research on that, and he, he was saying that, like, evolutionary psychology, he was kind of representing it as a monolith, and that, you as as a, as a monolith, we were saying, no, we reject the kin, the kin selection theory of homosexuality, um, that, but again, that's, that's not really what's happening, um, so Okay, I will tell you, I mean, but but I want to qualify this, like, the kin selection theory of homosexuality is an ev psych theory.

0:07:26 Thomas: Mm hmm.

0:07:46 Thomas: Well, what is happening?

0:07:56 Thomas: Oh, it is.

0:07:57 Lindsey: Oh yeah. Kin selection is like a huge explanatory principle in evolutionary psychology. There's a ton of research supporting it as a hypothesis, right? Like, as a general hypothesis, not about homosexuality in particular, but like, as a generally, uh, theory for explaining behavior, like, it's incredibly powerful. It, it, you know, it changed the, changed the study of behavior, um, So

0:08:02 Thomas: Hmm.

0:08:18 Thomas: Give us a quick refresh on on it. I remember as regards homosexuality, but I don't I can't think of off the, off the top of my head, like how it would apply to other things, but, uh, yeah. So give us a quick refresher if you don't mind.

0:08:19 Lindsey: Yeah. Yeah. Okay, so there was a classical conception of what genetic fitness meant that equated it with, um, a particular individual's reproductive success relative to the population. And so that's the way that fitness was conceptualized for a really long time, but then a couple of problems presented themselves, um, which were that, like, you know, know, people do things that are not in their self-interest, right? They engage in altruistic behaviors that are costly to themselves and that benefit other people. And that, from, you know, the perspective of this classical idea of fitness, everything that you should do should be in your own self-interest, right.

0:09:11 Thomas: Right.

0:09:12 Lindsey: But then kin selection was proposed, right, and raised the idea of um, of inclusive fitness. So this is the revised way to understand fitness. So under this conception, um, genetic fitness is not at the level of the individual. That's not where selection is taking place. Selection is actually taking place at the level of gene and you share your unique genes with other people, right? Your close kin. And so according to this theory, you should get certain behaviors that, um, um, that promote the the survivability and reproducibility of kin as well as of the self, right.

0:09:34 Thomas: Hmm.

0:09:48 Lindsey: Because It's, yes.

0:09:48 Thomas: So yeah. Okay. So I remember how that functions with homosexuality. It, it, it can, I think the theory was right that, fit males or females that don't choose a partner essentially and stay with the like family unit boost the fitness of those genes, I guess, right? So, are there any other, what other behavior besides homosexuality is possibly explained by this?

0:10:04 Lindsey: Yeah. Yeah. Well, I mean, helping behavior would be one thing. So people are, are much more likely to, um, to be altruistic toward people who share their kin than people who don't, and you also get, like, a linear relationship with helping behavior and the degree of, degree of, of, uh, genes shared. So, like, you're, you're most likely to help people that share 50% of your genes, which is your, um, your offspring and your siblings. And then you're slightly less likely to help first cousins, right. And then you're slightly less likely to help, um, second cousins, and so on, right? So as your relatedness with somebody decreases, you're, um, you helping behavior toward them decreases. And the idea is that, like, when you, you help somebody, helping your genes in their body, essentially, least in the case of kin selection, right? So, I mean, there's non-kin cooperation and reciprocity that we can talk about later if you want to. But yeah, that's the idea of kin selection. That we will do things to help our genes, regardless of whether they're in our body or somebody else's.

0:10:55 Thomas: Got it, yeah, right.

0:11:10 Thomas: Okay, so how did Carrier present it? Because I remember him talking about this, and then, so did he say that evolutionary psychologists are rejecting this theory, even though it's like a resounding success or something like that?

0:11:24 Lindsey: Yes, I think the quote was something like, what evolutionary psychology has done is get together and say, no, this is refuted, as though we have some sort of ideological stake in refuting kin selection, right? Which is not true. Like if, I mean, this hypothesis has a lot of intuitive appeal, and if the evidence bore it out, we would totally embrace it, right? And it still might. I mean there's a lot inconsistencies in the literature about what best predicts this. So you, I mean, and the funny thing is that like all this stuff is coming out in evolutionary psychology psychology journals, the stuff that provides evidence for it.

0:11:46 Thomas: Hmm. Right. So it's, so it's a battle within evolutionary psychology. So, it would be wrong to blame the field one way or the other because it is a, just a debate within the field, right? Is that what you're saying?

0:12:13 Lindsey: It is right. Just like any other scientific question, right? You're going to have people that have different perspectives on this and are trying to provide evidence for or against it. And eventually the side that has the most evidence on its side, you know, that'll start being taught in textbooks as like, yeah, this seems to have a lot of support for it, Right. But he, like he said that this was a classic example, example of evolutionary psych being a pseudoscience because they rejected this out of hand and ignored evidence, which just, it just isn't true. You even have like some of the same research teams that are testing this hypothesis across different cultures and they're finding inconsistent results and they're publishing on them. They're like, "Look, this is consistent with kin selection. This one doesn't seem to be consistent with skin selection." So it's, I don't know.

0:12:29 Thomas: Right.

0:12:56 Thomas: That's really interesting. So yeah, you can't possibly blame the field for that one, then it sounds like.

0:13:01 Lindsey: I wouldn't, I wouldn't call it a pseudoscience based on this, right?

0:13:06 Thomas: Sure. No, well, and, and to the contrary, that sounds like a healthy science if they're investigating the theory and publishing results that go either way, like whatever it is, they're saying, well, this is consistent with it, this isn't. So that sounds Like an emerging theory kind of thing. It's either going to stand the test of time or die, like you said.

0:13:22 Lindsey: Right. Exactly. Right.

0:13:29 Thomas: Interesting. I wonder why he thought that. Do you get the impression that he just accepts kin selection and then is therefore just looking at the people people arguing against it and saying like, oh, what are you doing?

0:13:30 Lindsey: Yeah.

0:13:41 Lindsey: I really don't know.

0:13:42 Thomas: Hmm. Interesting. It's just weird.

0:13:44 Lindsey: I'd like to hear why. I mean, it's possible there's something about this debate that I'm missing. And so Richard, if you end up listening to this, get in touch.

0:13:53 Thomas: Cool. Yeah. I bet I could, I bet it could make that happen. So what, uh, what is your stance on kin selection? Is it just kind of agnostic? Are you, you know, what does your personal stance on it?

0:14:02 Lindsey: About on kin selection selection in general or as an explanation for homosexuality?

0:14:05 Thomas: Yeah. Like, uh. Uh, I guess either. I don't know.

0:14:10 Lindsey: Uh, I mean, kin selection as a theory is incredibly well-established. Like this, this is a way that genes get passed on. Um, well, the preponderance of the evidence is on that side and it's a, it's very well-tested thing, not just in humans, but in other species. So it's, yeah, it's a very powerful explanation for behavior.

0:14:13 Thomas: Hmm.

0:14:28 Thomas: Hmm, but it's just a question of specific. Behavior that you're that that the theory is unsure on or that the evidence is not in so

0:14:30 Lindsey: Right. Yeah. Like, so you could potentially make the the prediction based on kin selection that this could be a way that homosexuality gets selected for. It could be akin selected mechanism. Um, but as far as I can tell, I mean, there's, there's evidence that's consistent with that and there's evidenced that's not

0:14:53 Thomas: How did it get established as a firm method of, what, of gene selection yet not established as, you know, like, what, so how was that established initially? Is it mathematical models or something statistical models? Hmm.

0:15:06 Lindsey: Oh, partly. Yeah. I mean. Um, so, I mean, so you can look at, there was a classic study with ground squirrels, and one observation that had been made about ground squirrels was that they tend to give off these alarm calls when a predator is near. Right. Now, these alarm call are great for the other ground squirrel, right? Because they know that there's predator coming, but it's not so good for the particular ground squirrel that makes that call because that will alert the predator to where they are and they'll get eaten. So from a kin selection perspective, you can make sense out of this maladaptive behavior by saying, okay, so if they're doing this call to rescue their own genes in other ground squirrels' bodies, then we should be able to see differences in likelihood of alarm calling in situations in which more kin or fewer kin are around, controlling for how many ground squirrels are around.

And there was a number of other alternative hypotheses that are not coming to mind right now. But they did studies in which they looked at the associations between likelihood of somebody admitting this alarm call. And one of the things that they looked at, the relationship between, was how many ground squirrels overall were there versus how many ground squirrels that were close genetic relatives were there.

0:15:08 Thomas: Yeah.

0:15:37 Thomas: Interesting. That's

0:16:30 Lindsey: And they saw that the alarm calls were more likely if there were a high proportion of genetic relatives around. No,

0:16:35 Thomas: Interesting, well how would that work, like how, do are they really somehow making the decision to make an alarm call based on that? Or just that isn't evolved, that hasn't been selected for as much, but how are you testing that environment? Like in the time it takes for that to evolve, you know, like we're testing just environments right now, right? Like how, how could you be sure that, you know, I guess I'm confused on how we would be able to know that. That well no, on how, so if, if I, I totally get the theory to make sense that if you, this alarm call, which is bad for the individual organism, you know, but is but is good for its kin, I get that theory to makes sense, but I don't get how you would say okay so let's test areas where there's squirrels with a lot of kin around versus not, and then know that, because like I would think, okay, this behavior has evolved in whatever species you're looking at, it and it would still apply regardless of the current environment of the squirrel.

0:16:42 Lindsey: Right. We that's true on how we'd know whether it was an adapted mechanism? Oh, No, I mean like, like, um, not not environment in a general sense, but like if you have a situation in which you've got a group of ground squirrels out gathering and a predator comes right like if that group

0:17:51 Thomas: Oh, so then it does modulate its behavior based on that then. So, it's somehow... Okay, so that was the first thing I said. So it's somehow changing the... It will change its behavior on this emergency call given how many kin are around. Okay. Sorry. I thought you said no to that initially, which was why I was confused, but I may have just spoken clumsily. Okay, so that's interesting. Yeah, totally makes sense.

0:17:53 Lindsey: Absolutely Yeah. Exactly. Yeah. So That's just an example, but but there's, there's been a number of demonstrations that you, you can predict behavior that on its surface seems somewhat maladaptive, or at least, you know, too costly to be sustained for the individual's fitness. But then when you look at it in the context of what that behavior is doing for close genetic kin, you could predict these, these costly behaviors, right, um.

0:18:42 Thomas: Right.

0:18:42 Lindsey: And that that holds in humans. Like, you, you see, um, if you do surveys of, um, like how, how likely people are to have done these very costly helping behaviors, or even risky helping behaviors, like saving somebody's life, um, disproportionately, people that are very close genetic relatives are the recipients of those behaviors as opposed to distant genetic relatives or non-kin.

0:19:04 Thomas: Interesting. Okay, then it's just the current testing now is just a question of trying to fit that model into different areas of behavior like homosexuality or whatever it is, and its test results are still pending on some of that. Okay. Gotcha.

0:19:15 Lindsey: Exactly right exactly right So that's like a theory that you can use to make predictions about specific domains of behavior, essentially, yeah, and it may or may not apply to a specific behavior. Yeah.

0:19:25 Thomas: So Yeah, I'll, I'll count that one as, I'm confused, I would need more information as to why you carrier thought that that was a strike on on evo psych when it sounds like it's from your description it sounds like it's just a debate within evo site and I don't know why you would fault one side or the the other. Yeah.

0:19:45 Lindsey: Or Rather like more than a debate, I just say that we're still collecting evidence on it. Right. And So I don't know that anybody's making particularly firm statements about out, you know, whether or not we can I mean, I might be wrong about this, the homosexuality question is not something that I, I spend, I've spent a lot of time looking into or researching, I just read a handful of articles for this, but as far as I can tell is still research being conducted at both, like, surrounding whether or non-kin selection is a good explanation for homosexuality, and there seems to be evidence on both sides.

So, so this, this was another point under the, you know, the testing theories idea, so one, one was what I just said, right? We, we actually test specific predictions and then if those hold up, they support theories. Right. But the other thing is that, so this was more an issue in his article than it was in the podcast, but there was a lot of him taking particular methods, um, sort of point by point and pointing out the limitations in each of those methods. Um... A lot of which which was valid, right?

0:19:49 Thomas: Yeah. One way or the other. Okay.

0:20:44 Lindsey: There are a ton of limitations to using self-report methods, for instance, or testing a question in a non-representative sample, right. All those things are true. But I think one of the things that he misses is that your, your evidence for a particular hypothesis or a theory comes from convergent evidence from a bunch of different types of methodologies. And all of those different methodologies have specific limitations, but they they have different limitations. They have complementary limitations. So if you find support from a variety of different methodologies that converge on a single explanation, you have very good evidence. But it seemed like the...

0:21:25 Thomas: Though you can pick apart like one of this, you know, you can say, oh, this study doesn't count on this or that. Yeah, take this into account. Okay.

0:21:26 Lindsey: Exactly. Exactly. Yeah. I mean, you can do that with every single study in existence. That's absolutely true. But if you take the cumulative weight of a bunch of different studies from different perspectives, you have of convergent evidence. So he was, it seemed to me, and I don't want to put words in his mouth, but like, it seems to me like he was saying, look, when you add up all these flawed methodologies, all you get is a bunch of flaws. You don't get any knowledge, but that's not, that's not really true.

0:21:57 Thomas: Yeah, it's sort of like just thinking back to Greatest Show on Earth, it's sorta like, like dating stuff, you know, when you're trying to date a rock or you're trying to data some sort of something, we had all these different methodologies, like tree rings, like, that we could date when a climate event happened, and it's like, well, there's could be flaws with that method, but then you compare it to another method of dating that shows the same results at the same period of time, even though that method may have its own flaws, the fact that they both show the the same thing is very strong evidence for that particular, like, time frame.

0:22:34 Lindsey: Yeah, exactly. Right. And I think that we're fairly, we're fairly cognizant of that in this field just because of, of the, there are certain certain difficulties when you're trying to argue that, um, a feature of the mind is an adaptation versus a feature of the body, you can see the feature of the body. You can't necessarily see the feature of the mind. And so, um because of that, like, I feel like we're pretty tuned into these problems. And we emphasize a lot like the power of convergent evidence. I'm not saying that other fields don't, but I'm saying this is a salient, um thing that we're aware of. And I, So I don't want people to think that we just don't know that it's important to do cross-cultural research, for instance.

0:22:34 Thomas: Okay. Yeah, that was one thing he kept saying, like that all these studies are just, you know, what was it, like white? Oh, what do they call it? I can't remember. Weird. Yeah.

0:23:22 Lindsey: Weirdos.

0:23:24 Thomas: White educate. Yeah, something or other. Yeah so what do you think about that? I mean, is that the case? Are there too many studies on just plain old white people?

0:23:24 Lindsey: White, educated, industrialized, something. Yeah.

0:23:39 Thomas: Normal,

0:23:39 Lindsey: A valid criticism if that's the only thing that you're doing. And I think that, you know, as a field, it has been pointed out many times, and it's very true, that a lot of the initial research in psychology was done on those types of populations. But I think that we might be less guilty of it in evolutionary than other fields. And the reason I say that is that we are often drawing on information that we've gathered from like anthropological studies, comparative studies, like comparative is in interspecies comparisons. Comparisons. So I think that, like, if you took a random sample of studies that are using cross-cultural methods within psychology, it's actually probably disproportionately more likely to be evolutionary. I don't know that for sure. I mean, and there is a lot of, like cross-culture research is an actual subdomain in psychology.

0:24:30 Lindsey: So maybe that's unfair. But we are very tuned into the fact that it's important to do that. Now, having said that, it is not true to say that it is completely valueless to do an initial study of an effect in, like, say, a population of United States college students. You need to put the appropriate qualifications on that, but you can gain valuable information from looking at that population, right?

0:24:58 Lindsey: So he made the point a bunch bunch of times that our current environment does not represent the ancestral environment. And that's absolutely true. And it's always on the forefront of our minds. But it doesn't represent the ancestral environment in very specific ways. And when you hypothesize about a particular psychological adaptation, you're making specific predictions about how that adaptation might manifest in the current environment a lot of times. So it's not like we just can't know how how an adaptation is going to interact in the current environment. That's not true. I can, I can give an example of a very, a very good area of research that I actually would say is, is one of the best examples that have come out of this evolutionary perspective on, on human behavior. There are many, but how do you feel about incest, Thomas?

0:24:58 Thomas: Oh, sure.

0:25:45 Thomas: Oh interesting. Well, I don't partake myself. No.

0:25:50 Lindsey: No. Any particular reason for that?

0:25:53 Thomas: Yeah, it just seems like it's one of those instincts, huh?

0:25:56 Lindsey: No, I mean, it could be cultural. That was a suggestion for a long time that it was just, you know, cultures have incest taboos and that's a thing, and so people don't have sex with their siblings because of that.

0:26:06 Thomas: Whereas like the Targaryens, for example, to name a different culture.

0:26:09 Lindsey: Oh my god. All right. Game of Thrones comes up so much in evolutionary psychology, you have no idea, all the time.

0:26:13 Thomas: Yeah. Is that I'm not sure if that's indicative of a pseudoscience or a healthy science. I'm Not sure.

0:26:21 Lindsey: Yeah. So, um, do you have siblings and you, you enjoy having sex with them on a regular basis?

0:26:28 Thomas: Yeah, yeah, semi, you know, as regular as I can, you know, it's not it's we're not available, you know, stuff like that. It's hard to find time. But yeah, sure. Sure.

0:26:41 Lindsey: Yeah, I could hear the disgust in your initial reaction, um, and that is fine, don't, don't feel ashamed. Um, yeah, no, I think that it's a fairly common thing that people feel disgusted by this, right? And so I want to, like, so for, for a very long time though, this was attributed to incest taboos, and so the, the idea was that, like, if you, if you didn't have these cultural mechanisms prohibiting incest, then people would just have sex with everybody, including their siblings, links um but in the late 1800s, um, researcher named Westermark made a observation, which was that people seem to be naturally disgusted by the idea of having sex with people that they've grown up with.

0:26:51 Thomas: Yeah. Yeah, yeah.

0:27:21 Thomas: Yeah. I was gonna say, like, I don't, I never in any part of my life can I remember anyone needing to tell me that, like, and I know that's anecdotal, but it's like I don't yeah my there was it would have been if that were true, it seems like it would be one of those things that your parents would need to tell you when you were like five, you know, because, like, yeah, because like toddlers are always like doing weird shit, like just, you know, pulling out their genitals and say, no, no. You can't do it. You got it. We're, you know. All this stuff that's culturally taught. But that's, I don't think that's something that really, I Don't know. Who knows? I don't t remember needing to be taught it, is the point.

0:27:21 Lindsey: Yeah. It is but but it's also important yeah and They'd have to correct you, you, right?

0:27:50 Lindsey: I, I, no, I have the same intuition, right. Um, but you know, it's just an intuition, right. So he, he suggested this very specific thing. He's like, maybe, maybe we have an innate mechanism that keeps us from being sexually attracted to the people that we grow up with. Right. So that's like a, that's a specific hypothesis about a psychological module and and how it will work, right?

0:27:59 Thomas: Yeah. Yeah. Mm-hmm. Mm-Hmm. Yeah.

0:28:19 Lindsey: Do you, do you know why incest is bad? Like, why? That's kind of more condescending than I meant it to.

0:28:24 Thomas: Well, don't our, yeah. Now, do you know? Now, honey, do know why? Yeah.

0:28:32 Thomas: Uh, do you mean like, um, biologically why it's bad or are you trying to get me to come up with a moral justification? Because that is interesting because that's it. This crosses, uh, disciplines because I know in moral philosophy, uh. This is something they talk about too, because it's like, this is proof that in some cases your philosophical justification comes after this feeling. You know, so like when you ask people like, oh, why isn't this bad? They try to come up with, you know, some explanation. And then you go, well, what about just the consenting brother and sister, you know, using condoms, no chance of, you know, and you go on down the list and people just still are like, nah, it's just wrong, you know. So

0:28:38 Lindsey: No, no, like, like.

0:28:56 Lindsey: Yes. Yeah,

0:29:14 Thomas: It's interesting.

0:29:15 Lindsey: There's. All right, we're gonna get into why that is, I think, or at least, you know, like...

0:29:18 Thomas: Oh, Well, I mean, it seems pretty straightforward to me, but yeah, okay.

0:29:21 Lindsey: Well, yeah, but, but so, okay, but... So, again, like the components of this explanation for incest avoidance are going to have a couple of different, there's going to be three different components, right? So there's gonna be the proximate cause of the adaptation. So why, why is it the case? Like, what are the mechanisms that keep us from finding our sibling or wanting to have sex with our siblings? Right. But then there's this other part of the explanation, the ultimate part ofthe explanation is like, well, why would, whywould selection pressures have have kept us from having sex with our siblings.

0:29:42 Thomas: Right.

0:29:52 Thomas: That's Because the the offspring is not quite not as fit, right? Like, isn't, don't our genes combine badly or something like that?

0:30:00 Lindsey: They do. Yeah. And this could be too much detail, but I can drill down into that a little bit. It's kind of interesting as to why that.

0:30:00 Thomas: Yeah. Uh, Sure. Sure. Yeah, I think I've read about it before, but I don't, I don't remember the details that much. Yeah.

0:30:12 Lindsey: Yeah, okay. So it's estimated that on average, any given person has between one and seven of what are called fatal recessive alleles, right? And if these alleles of these gene variants were expressed, they would have really, really bad effects, right? So a lot of the offspring with these expressed alleles would just die immediately, which is why they're called fatal recessives. But if they don't die immediately then they have very severe problems.

0:30:39 Lindsey: So all of us have one to seven of these kicking around in our genome on average.

0:30:38 Thomas: So, Weird. Yeah.

0:30:44 Lindsey: I know. But the reason that they're able to persist and they don't cause us any problems is that their expression is masked by a dominant allele that keeps it from expressing, right? So we can have these and have no problems and our offspring will generally have no problems. So if you're mating with somebody who's unrelated, right, or okay, back up. So the time when these fatal recessive would be expressed is when you have an offspring that gets two copies of the fatal recessive.

0:30:55 Thomas: Yeah. Yeah.

0:31:12 Lindsey: If you're mating with somebody who's unrelated, that's really, really unlikely to happen. But if you'RE mating with with somebody who's closely related, the chances of that actually go up a ton, right? And so you would expect there, like there must be like a really strong selection pressure to keep us from mating with close kin, right, because there's this, you know, you have severely reduced fitness in your offspring.

0:31:35 Thomas: Yeah.

0:31:35 Lindsey: Okay, so that's the ultimate reason. But the proximate cause of that that Westermark was suggesting was that it's not genetic relatedness per se, because we don't have direct access to that, right.

0:31:45 Thomas: Yeah. Yeah. We can't know that exactly.

0:31:48 Lindsey: Yeah. So instead, there's got to be some cue that ancestrally would have been related to relatedness, right? Something about kin, right, that would have given us a statistically accurate cue that we are related to that person and shouldn't select them as mate. And in the case of his hypothesis, he was saying that that mechanism was close childhood association.

0:32:12 Thomas: Right.

0:32:12 Lindsey: So if you grew up in the same household with someone, then it's highly likely that you are siblings, for instance, and thus you should avoid them as mate, right?

0:32:21 Thomas: So I would I would guess that you could predict that, you know, there is a chance of incest among there's a higher chance of Incest among siblings that didn't grow up together or something like that. Is that a prediction you make? Yeah.

0:32:22 Lindsey: Exactly. Yep. Um, and we'll get into some of that. So some of some of the research has been done more recently, um, but like in the 1970s there were a few, there started to be some research trying to to look at whether, like, to look in, uh, quote unquote natural experiments where you could separate out, separate out the incest taboos, um, from this element of growing up with someone, one being a barrier to sexual contact, right? So for example, Wolf did a study in Taiwan, and he was examining these two different forms of marriage, right, one in which two people get married as adults, right, and another in which marriages were arranged, like, usually at birth and Then the future bride moved into the house of the future groom, and so they were reared together. Other. And they were supposed to get married eventually.

0:33:15 Thomas: Wow. Uh huh.

0:33:25 Lindsey: So this is a situation in which the culture is explicitly trying to promote one behavior. And this hypothesized adaptation, if it really exists, should be prompting people to do the opposite. And so what he did was to look at the success and the fertility of these two different types of marriages. He used two two different data sources, right? One of them was objective and boring. It was the town records on like divorce and number of children produced, right, so that's good. That gives you a sense of the marital quality and also how many children they're producing, which should be related to how often they're having sex, But then he also got this other data, right. He developed a relationship with a contact who was local to the area, and he got this guy to tell him all the town gossip, which was awesome, right, I love this. It was like, so they had this nice quantitative element, but you also had this qualitative data, it gave you some insight as to, you know, how, why people were acting the way that they were.

So the the town record stuff bore out, right, you were more likely to get divorces in this minor form of marriage, you were most likely to get, um, like drastically reduced number of children produced from that minor form of marriage, and also those were likely to be overestimates because if there was cuckoldry going on, right, then it would probably be reported as a product of that marriage, but, yeah, but anyway, you did get a

0:33:39 Thomas: Hmm. Yeah.

0:34:47 Lindsey: Lesser production of children, but the gossip was really where it got interesting. So the the guy was telling him about how in this minor form of marriage, the parents of the new couple have to, like, lock them in a room together and they, like, stand outside the door and the kids will try to escape so they don't have to have sex with each other, and they're, like, beating them with a broom to get back into the room, and it's it's just, it's madness, they so don't want to have sex with each other at all, right?

0:35:13 Thomas: That's so weird.

0:35:14 Lindsey: And they are not related, but They Do have this proximate cue to relatedness. And it seems to be a very strong predictor of this resistance, right. So this, they they looked at other, um, similar, like, cultural experiments and other studies, um, so they looked at, um, there's a structure, and see, this Lebanese father's brother's daughter's marriages, so this, this is where they promote marriages between, I think it's usually first cousin or second cousin, but the cousins are reared together like siblings, and you get the same kind of effect. They've looked at Israeli kibbutzim, right, where the kids are raised in classes together, generally not related, right? But they don't consider themselves to be appropriate marriage partners, even though the culture is, if not promoting, then at least not discouraging marriage within your, right, essentially. So you've got all these, these countercultural examples, um, in which the behavior is lining up with this evolutionary prediction.

0:35:16 Thomas: Yeah. Yeah. Yeah.

0:36:06 Lindsey: Now, more recently, um. Researchers have, have tried to look, look at this a little more closely and try to refine our thinking about, um what the adaptation looks like a little bit more closely, right? So, um Beck and Silverman, for instance, did a study in which they, um put out an ad and said, hey, we're interested in knowing about sexual contact between siblings. If that's you, please write in. So they collected the sample of people that were very likely to report having had some sort of sexual contact with their siblings. And then they were able to look at code the types of sexual behavior. So was it actual behavior that could be reproductive? So penile vaginal intercourse? Or was it Or Was it manual stimulation? Was it playing doctor? Right. Those kind of things.

0:36:52 Lindsey: And so they looked at this as a function of whether or not the children had been separated for some period of time in childhood or whether they'd totally grown up together for, like, their entire childhoods. And what they found is that, you know, among the people who reported that they'd had penile vaginal intercourse, potentially reproductive success or sex, those people were disproportionately more likely to have not grown up together or to have been separated for some period of time during their childhood, but And this is the interesting part, the other stuff wasn't predicted by that, um, and so, like, yeah, it's actually not totally uncommon for siblings to experiment with each other sometimes, exactly.

0:37:18 Thomas: Yeah. But not in the, but not in a way that could lead to offspring. Usually. Interesting.

0:37:35 Lindsey: Exactly. Right. And so this was sort of a, it was a refinement of the Westermark hypothesis, they were saying, you know, it's not necessarily a lack of sexual behavior in general, it seems to be a specific barrier to prevent potentially reproductive sexual activity. Yeah.

0:37:50 Thomas: Huh. So interesting.

0:37:53 Lindsey: And this isn't the only mechanism that seems to be an overdetermined thing. So if you're an older sibling, you have the benefit of being able to see your mother get pregnant and then give birth to the child and nurse the child. And so that's actually a better statistical cue to relatedness. And that tends to be a strong wrong predictor. And when you have that, then the childhood co-residence doesn't predict things as strongly. Right. Which is interesting. But it implies, right, that this is sort of an overdetermined thing to keep us from having sex with our siblings.

0:38:11 Thomas: Oh, okay.

0:38:25 Thomas: Right. Right. Now, I remember, I think at one point Dawkins said, if we, if we just started doing it and then the, because of the, the, like you said, the recessive alleles, if we just allowed selection to take place on the offspring, that it would go away, like eventually, after a bunch of offspring died off, like, horribly, and it would be very unpleasant, that would go away, and we could just reproduce with our siblings, which is the weirdest thing to think about, it's weird, too, yeah, no,

0:38:26 Lindsey: Right?

0:38:44 Lindsey: That's true. Yes. Mm-hmm. I know. I'm not particularly, I'm particularly motivated to make that an actuality.

0:39:01 Thomas: Yeah, I think we're good. How we are, but it's so interesting that, like, we could, it's such a strong intuition and instinct against it, but we could make it go away if we, for some reason, really wanted to. It's kind of interesting. I mean, it wouldn't, it wouldn't be us, but, yeah, yeah, Yeah, weird. So, how the hell did we get on this? What was this about? Right.

0:39:03 Lindsey: Yeah. Yeah, we could. I mean, they've essentially done that with lab rats, right? Right. Yeah. Oh, I just wanted to give an example of some really good research that has really good convergent evidence. And, you know, there's... there's elements of these countercultural examples that, you know, have weaknesses. Right. I mean, they're not they're not as rigorous as you can get with other types of methodologies. But you put all these different things together and you've got pretty good evidence that incest avoidance is a thing that it's innate.

0:39:46 Thomas: So, it's, and it's not a cultural thing, and it actually just pretty much defeats the cultural, uh, like, like in the cultures you describe where they're trying to encourage, uh, marriage between, uh, close, not siblings, but, but people who yeah, yeah, live together or whatever, whatever, reared together, that it actually can pretty much defeat that almost. It's almost stronger, the drive to not reproduce with your sibling.

0:39:48 Lindsey: Yeah.

0:40:01 Lindsey: Pseudo-siblings. Right. It is very strong evidence for it.

0:40:15 Thomas: Interesting.

0:40:16 Lindsey: And as we collect more information on it, our ideas about how this works gets more and more refined. I mean, for instance, one possible hypothesis about incest avoidance would be that we recognize each other based on body odor, right? Other species do that, like hamsters, for example. They do that, um, and there's, like, some very, there's weak and kind of inconsistent evidence for humans indicating that we discriminate based on body odor, um, but it's, it's not nearly as strong as these, as these other proximate causes, or as the evidence for these other approximate causes. So, yeah. So, oh, yeah, well,

0:40:51 Thomas: So I guess we're kind of running out of time here. So maybe we could cover some, just generally. I'm wondering, how do you see, when this big debate comes over sex differences and all that, what do you, you see as, as in general? I, I don't know. I mean, you got one side that thinks that everything is just culture, and the, and, and presumably another side that, that tends to emphasize, no, there's evolutionary differences between men and women or whatever. Where do you stand on that? Or is it just, is there anything significant that you see as a major implication from that? Are you just basically wanting to go with wherever the experiments lead us?

0:41:32 Lindsey: I'll say two things, um, one is that, is that what an evolutionary perspective is doing is not saying it's biology, not culture, right? It is, it is a highly interactionist perspective. So every hypothesis that we make is, um, within the context of a certain environmental input or cultural constraint. I mean, it's a very highly interactionist point of view, right. Essentially, like I, sometimes I see the other side of this debate as kind of being blank slatists, and that, that might be a little bit unfair for some people. But what I feel like I'm arguing against. Not that culture is influential, but that it's the only influence. But the other thing to say is that, yes, I want to know what's true. I want to know what the biological contributors to certain things are. Um, and I think that having a better understanding of these mechanisms can only help us in trying to create unbiased systems, like, for example, we know that we, um, we're really good at stereotyping.

0:42:30 Thomas: Go.

0:42:31 Lindsey: We're real, real good at that, and so that's probably that's the reason.

0:42:35 Thomas: Us. Yeah.

0:42:36 Lindsey: Yeah, I know, but, like, that's, that, when you hear, when you see a headline that's like, study shows that, you know, men are different from women on this cognitive capability, that people are like, oh, no, now there's going to be institutionalized sexism. But what I really think we should be drawing from that is saying, OK, so we know we have these biases, and most of us don't want to discriminate on the basis of these biases. That's a value that most people have, I think. Right. But we also know that they are influential, even if we don't necessarily want them to be. So even if we want to have gender equality in our hiring practices, we know that those biases can creep in.

So what I would say is that we need to figure out ways to create more unbiased systems in hiring and in jury decisions and stuff that incorporate our knowledge of our likelihood to stereotype and make bad decisions on the basis of proximate rather than things that are actually relevant to the discussion. Right. Like with the jury thing, for instance, even if the jurists are really, really motivated to only attend to the evidence, there's very good evidence that the race of the person

0:42:49 Thomas: Yeah.

0:43:43 Lindsey: Who's on trial and the gender and even the attractiveness of the, the person who's on trial, all influence jury decisions. So one thing we might think about is like, okay, rather than just telling people over and over, don't be sexist, don't be racist. Maybe what we could do is reconsider whether we really need the defendant in the courtroom.

0:43:49 Thomas: Yeah.

0:44:04 Lindsey: I mean, if we could blind this process a little bit, we'd have a better shot at reducing some of the systematic discrimination.

0:44:03 Thomas: That would be good, I wonder if that would have its own consequences, like, we'd feel less empathy, so therefore, you know, like, I wonder if that could result in more guilty verdicts just because we don't see the person, so we don't care about what's going to happen to them or something. I don't know. That'd be interesting. Yeah.

0:44:25 Lindsey: That's potentially true. But I mean, I think you, you could argue that are very aware of the role of empathy in those decisions and that they try to take advantage of it and use that. I think you'd have a better shot at getting more unbiased, or, like, more attention to the evidence that's relevant, and less attention to these superficial details. But, you know, I mean, there's probably logistical problems with that too. I'm just saying, like, if you're coming at it from that perspective and you're clarifying in your mind the distinctions between these different issues, I think that we have a better chance of moving forward in a positive way and trying to reduce these things that we all agree are bad. Discrimination is bad.

0:44:35 Thomas: Yeah. Interesting. Interesting.

0:45:03 Thomas: Yeah, well, uh, is there anything else you didn't get to that you want to address as regards the Richard Carrier episode? Oh, I

0:45:11 Lindsey: A massive amount, however, yeah, I recognize we don't have unlimited time. So I put together a folder of articles, and this includes some of the articles that we talked about today, some of the primary research articles. And there's also some review things in there that, for anybody who's interested in this area and wants to get a better sense of what evolutionary psych is like, they can go look at this. So um, so I'm requesting that, I'm going to send you the link to a Google Drive that has all of those in there, and if you wouldn't mind associating that with the show notes or whatever.

0:45:35 Thomas: Like it, oh, Absolutely. Yeah, that's, that's really cool. Thanks for doing that. I appreciate it. So, we'll be able to check that out on our own.

0:45:43 Lindsey: Yeah. Yeah. Absolutely. Thanks.

0:45:51 Thomas: And now I feel I've completed the set. We've got, I'm glad it took a little while, but I'm glad you emailed me. I'm glad that we were able to do this so that we've got both sides on this view and on this topic. And thanks for that. I really appreciate it. And it's oh, my pleasure. My pleasure. I love to learn, learn more. And it's good to get someone who is actually in the field to defend it. Yeah, sure.

0:46:06 Lindsey: For having me on. This was, this was great. I really enjoyed it. Yeah. And people should not take my word on this stuff, right? I mean, they, they should go back to the articles and see what they think. I put the monkey studies in there too, by the way, in case, so.

0:46:24 Thomas: Awesome. Yeah. No, I like it. Thanks so much for joining me, Lindsey. And I guess that's that's all there is is to it. Thanks for giving us the other perspective, and I'm really glad that we can make a more informed decision on this kind of thing now.

0:46:38 Lindsey: Awesome, yeah. Thank you.

0:46:50 Thomas: All right. Thanks to Lindsey for a great week of episodes there. There was a lot in the Richard Carrier interview that we didn't get to cover here, and that was because I had a lot of questions about things in general that I probably distracted the conversation with, but I was very curious to learn more about evolutionary psychology. So I'm I'm glad that Lindsey indulged us, and that was really cool. So I want to thank my new patrons. Let's see. Here we go.

Dead Eye, no, I think I think it. Jesse, Crystal, and Benjamin Badger are my new patrons for this week. Thank you guys so much. I really appreciate the pledge. Hope you enjoy the new bonus content. And I got to thank My All-Time Greats, Hunter Ash, Jesse, Inciting Incident Podcast, alongblackcock, Blackhawk, Kaylee Razor, Zimu Zinu, Adrian Borschoff, Jonathan Moyet, Jay Aldenwalt, Blackhawks, Aeroscience Sharks, Franco Villarreal, Steve Sigmund, Peter Skelton, Brian Gareford, Dale, Matt Garrett, Ian Rosano, Samantha. Thank you guys so much for pledging an amount that dictates I have to thank you every week, which is my absolute pleasure, because you guys are the best. All right, I'm very excited. You guys should be, if you could only know, very excited for things to come. Patrons will learn about them sooner than non-patrons, but in any case, it should be cool to see you next week for some great shows and a cool announcement. Alright see you then.