Death, Disease, and Politics ｜ Dr. Randy Thornhill ｜ EP 184 (6DqJ1Wv6EtQ)

https://youtubetranscript.com/?v=6DqJ1Wv6EtQ

So neoteny is the tendency of an organism to evolve towards its childhood Appearance. morphology. Yeah. And so, okay, so neotenous Neotenous averaged females are more attractive. Yeah. And so now is that just out of curiosity? Do you think that the attractiveness of that neoteny is a consequence of the ability of the more childlike face to elicit care from a male? Yeah, elicit care and interest and you know attractiveness. Neotenous averaged females are more attractive. Yeah. And so now is that just out of curiosity? Do you think that the attractiveness of that neotenous averaged female to elicit care from a male? Yeah. And so now is that just out of curiosity? Do you think that the attractiveness of that neotenous averaged female to elicit care from a male? Hello everybody. I’m pleased to have with me today one of the world’s great biologists. Dr. Randy Thornhill. He’s an evolutionary biologist and distinguished professor of biology, emeritus at the University of New Mexico. With a primary interest in animal behavior and psychology as well as human behavior and psychology. Dr. Thornhill and his colleagues have authored or co-authored about 250 scientific publications, including four research monographs or books. His publications have been cited in the scientific literature more than 35,000 times. A citation score is the number of times a reference to a given piece of research is cited by another researcher or in another publication by the same author. A scientific citation count in the tens of thousands clearly indicates that a researcher occupies a position in the upper echelons of scientific influence. Dr. Thornhill is a founder of the research disciplines of behavioral ecology, evolutionary psychology, evolutionary aesthetics. That’s the study of the experience of beauty from an evolutionary perspective. Evolution and human behavior, the modern study of adaptation and the study of sexual coercion. Dr. Thornhill, thank you very much for agreeing to talk to me today. Thank you for inviting me. Pleasure to be here. Thank you. Thank you. So I’ve come across your research a number of times in my career struck by its originality and its impact. I’d like to ask you first about something I probably ran into. Maybe it’s 20 years ago. Maybe it’s 15, something like that. You did some work on the perception of attractiveness, bilateral symmetry, averageness, and sexual selection. Can you outline what you found and why? Yes, I did work some years ago now in human attractiveness and that turned out to be very productive about attractiveness in general in animals. One of the key traits that animals look at in judging physical attractiveness of partners of mates is bilateral symmetry. And a colleague and I in the early 90s came up with a way to measure facial symmetry in humans. It had been worked on before and but the measurements that they used didn’t work. So we came up with a method that did work measuring bilateral symmetry in the face. So that is the symmetry of the two sides of the face. Why is that important? And why is it a marker for attractiveness? It turns out that that bilateral symmetry is a measure of developmental health. And so the the organism when it starts developing it’s designed by evolution by selection to to achieve a bilaterally symmetric form. You can think of that. This is the case, I want to say organisms, I mean all forward moving organisms. All forward moving organisms have have adaptations, developmental adaptations to achieve a bilaterally symmetric body because first of all that reduces drag. So if you’re moving forward and you’re bilaterally symmetric you don’t have any drag in your movement. You can think about a person with a leg a bit shorter than the other and there’s drag in the forward movement. The more of that asymmetry the more drag. So you lose efficiency and movement. That’s fundamental to what bilateral symmetry is about. But next bilateral symmetry is very hard. Perfect bilateral symmetry is very hard to achieve by development. So it’s a marker of quality of the individual pertaining to its developmental health. We see in many things that human beings design to move forward bilateral symmetry. Cars are automobiles are bilaterally symmetrical, airplanes are bilaterally symmetrical. So we like our world to be that way. Yeah, we like to be that way actually it turns out. And well we’re associating it with the same principle. If you had one side of the car asymmetric compared to the other side of the car, then there’d be more drag. You know, it’s not an efficient, you’d use more gas. Think about it that way. So you’re not going to have a lot of drag in driving down the road with an asymmetric car. But so this this is one component of physical attractiveness. Bilateral symmetry. And we looked first when we developed this way to measure facial symmetry. That became a very hot research topic. We did the first and then others followed very quickly. Lots and lots of research has been done now, but there’s, you know, symmetry of movement that’s important in how fluid one’s movement is and how attractive therefore one’s movement is. You’re not dragging your foot or whatever. And all that is really a component of the importance of health in physical attractiveness. So physical attractiveness fundamentally is a health certification. That’s how we judge people’s attractiveness. We don’t think about it consciously. It’s an unconscious calculation of the traits important in health and developmental health as bilateral symmetry is one of these. So you measure the symmetry of the two sides of the face. And we showed in our first study of this way back now that that measurement relates to how attractive faces are perceived. Try faces in the same sex or opposite sex. And then that’s research went on to look at kids looking at faces and different ethnic groups looking at faces. It works like a charm wherever you do it. Lots and lots of research. And so does it mean that if you show people symmetrical or asymmetrical faces that they obviously have a preference for the symmetrical faces, will they look longer at the symmetrical faces? Will infants look longer at symmetrical faces? Yes, they do. Yeah, that’s the way the infant beauty research is done. You just look at whether the baby and they got it down now to almost newborns, you know, looking at faces and judging these faces basically on the basis of interest, how long they look at the face versus getting distracted to something else. And symmetry is one component part of the beauty, whether you’re talking about babies or kids or old people or young people or whatever. Facial symmetry is very important. It’s not the only beauty marker in the face we look at. We can talk about that in a moment, too, because that gets us into some other research we’ve done. But symmetry is a very important one. That research went on to look at how symmetry plays out in the everyday lives of people. And we did the initial studies on that. But again, that research bloomed and lots of people have done it and still it’s an active part of research. But the first thing we did, not just attractiveness, we did a bunch of that in relation to symmetry, but we looked at sex lives of people, romantically paired people, studies of couples, and looked at reports by men and women of sex partner numbers they’ve had in their lifetime. That was one component of it because that’s a measure in men in particular of what biologists call mating. So a number of sexual partners one has. And that research showed that for men, the more symmetric the man, the more sex partners he had. And a technical tale there, after we initially started with facial symmetry, but then we moved to the body of people. We came up with a very interesting model. We came up with a metric for body symmetry, measuring 11 traits on both sides of the body. These traits are ear length and ear width. And then we measure elbow. There’s an elbow anatomy there that we measure some bones, wrists, fingers, all those. Men measure of course on both sides. Measure foot width, ankle width, traits like that. And we put that together in a composite as a measure of body bilateral symmetry. That correlates highly with facial symmetry because the symmetry is a developmental health measure throughout the body. And that correlates with mating success of men. More symmetric men are physically more attractive and they have more sex partners. We also got into looking at men’s infidelities in their relationships and found that more symmetric men engage in more matings outside the pair bond as well. So that’s part of their mating success. We did the first study of kind of modern study, we would call it, of female orgasm in copulatory orgasm. So in part, looking at women, 200 romantically paired couples, and asking the women about their orgasm patterns during mating with their partner and separately asking the men. And we found that the men’s reports and the women’s reports of frequency of copulatory orgasm by the women were very highly correlated. So men are paying attention to this phenomenon of whether the female is sexually aroused to the zenith level of orgasm, of course. And more symmetric men were firing more copulatory orgasms too. That was a very classic study in human sex. I have a specific question about that. I’ve always wanted to ask a biologist interested in sexual behaviour, but I know that there’s been a lot of discussion about the hypothetical evolutionary purpose of female orgasm. I was wondering if female orgasm is disproportionately likely to trigger male orgasm. Because it could be an adaptation that’s used to elicit pregnancy, essentially. Yeah, I don’t think it is. There’s no evidence that females that orgasm very infrequently have fewer babies. And actually women who don’t ever orgasm can be quite fertile. So I don’t think it’s fundamentally that. I think what it is, is it’s part of female mate choice and more basically sire choice of the female. Let me explain. So when a female has an orgasm, she has uterine contraction, of course. And that pull, it works like a suction. It pulls the content of the vagina up to the cervix. So it puts the content of the vagina in a good place. And if that content includes the male’s ejaculate, then she’s pulling the male’s ejaculate up to the cervix, where it’s easier for him to get, you know, either for the ejaculate to get into the right place to conceive. So if she, imagine a female who has two mating partners. She orgasms with one, pulling his ejaculate up to the cervix, and she skips orgasm with the other partner. So she, in effect, is mated with both men. So that is, you know, same mating success of the two men, if you just look at mating success. But she’s doing something more subtle that is differentially affecting the fertilizing capacity of the ejaculate of the two men. The ejaculate she pulls up, has more potential for fertilization. And that’s a component of cryptic female choice. So in the 80s, I discovered what I labeled as cryptic female choice, first in insects, and then it applied to female orgasm too in humans. As cryptic female choice is just the kind of female choice that is invisible if you’re only measuring mating success. So in the example we talked about, the two guys mating with this female had the same mating success, they both mated with. But one was preferred over the other by the female’s orgasmic capacity with him that pulled his ejaculate up. And so females, by showing this differential orgasm pattern that I described with symmetry, are favoring symmetric partners over other men. And hypothetically healthier partners and with an advantage. That’s right, higher genetic quality. And then that’s an issue behind all this discussion so far, is that female organisms are after high genetic quality partners to be fathers of their offspring. So it’s a sire choice. A cryptic female choice is more of a sire choice than just a mate choice. And Charles Darwin discovered female choice and did a lot with it, for sure. And biologists had viewed female choice in a Darwinian framework up until very recently, until cryptic female choice came along. But females are far more sophisticated than just choosing one male over another as a mate. They do these subtle things involved in cryptic choice to prefer the sperm of some mates over the sperm of others. Now that’s a big area. What other elements make up cryptic choice? You described orgasm. What else? First discovery was in some insects called scorpion flies. And what the females do there is they adjust mating duration, enhance the amount of ejaculate that the male transfers. There’s no orgasm in these insects. But the longer the male can mate, the bigger his, the more sperm he transfers to the female. So females are adjusting ejaculate duration on the basis of body size of the male. So bigger males are more fit males and so forth, better growth and more resources growing up, they’re higher quality males. The females are receiving more sperm from bigger males. That’s one thing I did with these insects. Another was the female, after she mates with a male, makes a choice of whether to lay eggs or not. If she chooses to lay eggs, then she will fertilize, we know from other research I’ve done, she will fertilize those eggs with the last male sperm she mated with. So if she makes the decision to lay eggs, she’s going to use that last male sperm and large males again are preferred in that component of cryptic female choice. So cryptically, these female scorpion files are preferring large bodied males by both receiving more sperm from them and making decisions to lay eggs with them and not other males. So those kind of subtle things that females do that aren’t apparent if you’re just measuring classical mating success. And is symmetry in human beings, is it associated with longevity? Is it associated with decreased probability of disease in the future? Is it associated with higher general cognitive ability? For cognitive ability, we did that. We did that research and there have been three or four repetitions of our initial research. We dated on 200 subjects, similar age, so university students, psych who will kind of study and measured IQ using a culture fair measure of IQ, culture fair procedure and questionnaire, measured the IQ and then measured the symmetry in it for both sexes. The higher the symmetry of the individual, the higher the IQ. Do you remember the size of the relationship by any chance? That one was about 0.3. It’s a moderate relationship for IQ. There’s measurement error in measuring IQ. There’s measurement error in measuring developmental stability as symmetry too. So we measured 10, 11 traits. If we measured 50 traits, presumably we would get a correlation of say 0.8 with IQ. You know what I mean? And the IQ relationship would exist hypothetically because the healthier individual would be prone to a more favorable pattern of neurological development over the course of life. That’s the idea. Exactly. Some colleagues went on to look at some brain features in relation to developmental stability of the outer body. So they did brain imaging studies to look at certain brain parts. Some brain parts are bilaterally asymmetric by design. So one bigger on one side and corpus callosum is a tube that connects the two hemispheres. That’s just a size factor, but you can measure the size of that circumference of the corpus callosum as they did. And the bigger the tube, the higher the body symmetry of the person, bigger the corpus callosum. They measured a couple of other brain parts too and showing that… So you can talk about a modal directionality for an asymmetric trait. So there’s a mode, the most common degree of asymmetry in an asymmetric trait. So like handedness and so forth. The average person or the modal person is 60% right, 40% left, hand use. You can measure deviation from that as another measure of developmental instability. And that was the kind of thing they did with the brain parts, these asymmetric brain parts. So that’s deviation from averageness in a sense. In a sense, yeah. Now you also did work on averageness. Yeah, modal. Now you also did work on averageness and detractiveness. It’s some stuff with averageness, but we’re really just to control it because you can do average facial features, nose size, eye size, lip size, measurements of face. Right. And people have built composites of faces to produce average faces and had people rate them. Average faces is more attractive than non-average. However, average is not the most attractive face. The most attractive faces deviate from average in predictable ways. You want to talk about it? Sure. Yes. I’ve seen averaged models faces and they seem more attractive than averaged faces. And maybe that… Well, yeah, but you can take a model and you can make her a knock drop dead by the following computer manipulations. What you do, if she’s a female model, not a male model, if she’s a female model, you do the estrogen modifications on her face through computer techniques. So you reduce basically lower face size, chin size, jaw size, those kinds of things that are under estrogen control during puberty and adolescence. And for a male face, you manipulate in the opposite direction. So male faces are more attractive when testosteroneized, not estrogenized. And female faces are more attractive when estrogenized. So the female model, facial models, get their job because they’re highly estrogenized faces. And are they neotenous? The female attractive faces? Are they more neotenous? Yeah, they’re more neotenous in a sense of… So a woman who makes her living with her face, face model, her face is about the size, lower face is about the same size as a 10, 11 year old girl. So neotenous in that sense. So neotenous is the tendency of an organism to evolve towards its childhood morphology. So neotenous averaged females are more attractive. And so now is that just out of curiosity, do you think that the attractiveness of that neotenous is a consequence of the ability of the more childlike face to elicit care from a male? Yeah, elicit care and interest and attractiveness. So basically, here’s the way we think it works. So the neoteny we’re talking about, we could talk about it just as degree of estrogenization of the face. That’s what we measure. That is a marker of health in a different sense, hormonal health. So estrogen. Estrogen is fundamentally the fertility and reproductive capability hormone of the female mammal, estrogen. So the more estrogenized she is, the greater her fertility and reproductive capacity is. So that’s what we’re responding to in the physical attractiveness of a female. Is there an association between averaged neotenous faces and optimal waist to hip ratio? Yeah, well, yeah, the estrogenization affects not only the facial features, it affects bones and so forth. So, you know, petite, people talk about petite women as attractive, she’s so petite and so forth. What they’re talking about is estrogenization of the bones throughout the body, not just the face, but and that includes the waist-hip ratio is really a marker of degree of estrogenization of the female body, low waist-hip ratio. So a small waist relative to a more expanded hips, the smaller the waist relative to the hips, is a marker of estrogenization of the female body. And that again is a marker of female reproductive capacity through the estrogen effect. And that’s optimal at about 0.68? Is that research reliable? Yeah, your, you know, underwear models, female underwear models, they’re down, they could go as low as 0.66, 0.68, you can be a model. Yeah. So what other elements of attractive, okay, so a couple of things here. So the first thing that’s really quite interesting is that your work points to, or this work, this entire line of work points to a profound biological basis for the experience of aesthetic attraction, at least in relationship to the perception of other people, and of course, the perception of ourselves. That’s a tremendous amount of that’s grounded in instinct, apparently. Yeah. And it’s an instinct that’s manifest so early that you see the preference for attractive faces, say measured by averageness in newborns. Do you see the same preference for testosteroneized males and estrogenized females among newborns? Or has anyone looked at that? Yeah, yeah, yeah. Kids and down to very recently born kids have been looked at in terms of their judgment of men’s faces too. And that’s, they’re looking at testosterone features there, you know, you could call it masculinity would be the common, but testosterone technically. And these features that grow under the influence of testosterone during puberty and adolescence in the male, and in the female, they’re growing under the influence of estrogen. Basically, estrogen just capping the growth of those facial bones and the other bones too. And so, but testosterone along with growth hormone promotes the growth of the same bones in the face and body of the man. And so babies are judging men’s faces the same as you and I are a first off the street boy. That’s what the research shows. Yeah. This was promoted, there’s a book called The Beauty Myth, for example, that purports to claim that conceptions of female beauty are, what would you say, arbitrary social constructions. What do you think about that idea? How powerful is the biological impulse towards aesthetic experience? It’s the reality. The biological research I’m referring to has been so abundant since the really starting in the 90s that what really kicked it off was stuff we did initially on symmetry. And then researchers got into the hormone markers, beauty markers involving hormonal health. And then most recently, there’s been another drive to look at some pigment issues in terms of a beauty marker, a carotenoid pigment in particular. But it’s all health. It’s all health. And the beauty myth gal, I forgot her name. Naomi Klein. Yeah, right. That was just blank ideology, ranting, had nothing to do with reality. And then there was enough known about sexual selection processes and animals to cast that idea in doubt. But since then, it’s just… Well, because you see this, the preferences that you’ve been describing, you see analogs of those and variants of them across the entire animal kingdom. And you see the preference in newborns. So it’s pretty hard to construct a social constructionist view of the aesthetic experience of attractiveness, given all that information. Right. Well, the first study on symmetry that I did, the role of symmetry in sexual selection, competition for mates and mate choice, that was done on insects. At the same time, unknown to me, a Danish biologist was studying barn swallows and tail symmetry and barn swallows. And we co-discovered this role of symmetry in sexual selection independently. He was working on barn swallows in Europe. I was working on scorpion flies. And then I got into humans too. But yeah. And then following that, biologists working on all kinds of critters looked at the symmetry paradigm in their favorite study animal. And I think by 1997, 98, 75 species of animals that had been shown in which symmetry plays an important role in the sexual selection system of the animals. Yeah. So it’s very robust, to say the least. So fundamentally, we use markers of attractiveness across both sexes to indicate general health. And more than health, is it also an indicator of general competence? It’s associated with general cognitive ability. What about personality markers? Has anybody looked at that? Are people who are symmetrical? Are they less likely to be high in negative emotion, for example? We looked for it. The guy did most of the research on sex and symmetry in humans. He’s a psychologist and works in the psychology department. I’m a psychologist too, but I don’t work in a psychology department. And we got right into looking at personality, thinking it might correlate with personality and nothing. And others have tried it too. So symmetry is not part of the personality paradigm. Yeah. Yeah. Well, it’s not obvious that there’s an optimal personality. Perhaps that’s part of it, is that there seems to be niches for personality that are useful for all sorts of different personalities. I mean, it looks all things considered like higher general cognitive ability is better across multiple domains, but it’s not so obvious with personality. So maybe that’s part of the reason that’s not so robust. I was wondering more with sensitivity to negative emotion, because I thought maybe that less healthy people would be higher in trait neuroticism and that might show up with symmetry, but you haven’t found anything like that. No, we didn’t. We didn’t find anything that was condensing there. I see what you’re saying, though, that would be a reasonable prediction to get into. And in the personality domain, we can get into that when we start talking about the parasite stress. Yeah. So let’s move into the parasite stress theory now. Before we do, let me just summarize the beauty thing in two minutes. Great. So the current knowledge, the reality about our judgments of physical attractiveness, empirically based knowledge, the own kind of knowledge, there’s real knowledge, but empirically based knowledge of how we judge physical attractiveness in terms of facial and bodily attractiveness is we use health markers. And those health markers are developmental stability, that’s symmetry, hormonal health, that’s another one. And senescence is a third. So as we age, we lose attractiveness, of course, and we lose function, too. And so we pay attention to age and senescence effects when we judge attractiveness, of course. So symmetry, hormonal effects, and senescence. Then the final one, the most recent marker of physical attractiveness that has been discovered is the carotenoid pigment thing. And it’s pretty wild. So carotenoids, you can’t make, animals don’t make carotenoids, you get them from diet. We eat carotenoid-based foods or animals that have eaten carotenoid-based food. So you get all of our carotenoids, and the carotenoids are very important in metabolism. So fundamental to metabolism, you got to have a lot of carotenoids. If you’ve got a lot of carotenoids, then you’ve got excess carotenoids, you put those carotenoids in your skin, and then the yellow colors in skin, the yellow tints in skin, and doesn’t have anything to do with what your racial background is or whatever. There’s yellowness in the skin of African Americans, Caucasians, or whatever, Asians, there’s yellow pigment there. The degree of yellow is important in attractiveness. We assess it when we look at faces. The more yellow, the more carotenoid the person has, the more excess the carotenoid the person has, can put it in their skin. And what carotenoid says is that you have to have a healthy gut to absorb carotenoid. It’s fat soluble, and you can’t absorb fat if your gut’s sick. So the yellowness in skin is another marker of health that we use, and that’s only been discovered in the last 15 years or so. From what foods are carotenoids derived? Fruits and vegetables, they’re full of carotenoids, so you want to eat a lot of those. Is it also a marker of your ability to provision yourself? Well, that too, but you can provision yourself with anything. It doesn’t show up in your skin. That’s not a higher quality marker of provisioning, it’s a sign of metabolic health. If you’re a healthy body looking, that’s a good indicator, but this is specifically related to your overall gut health. So is it reasonable to say now that we know enough about the biology of attractiveness that we could build an optimally attractive form purely based on the scientific data pertaining to health markers? We’d look at ankle measurements and symmetry and waist-to-head ratio. I can take a female model, famous facial model, and digitize that face into the computer, like off the cover of Cosmopolitan or wherever, and I’ve done this. I can make her even more attractive through increasing the estrogenization components of her face. I can make her more attractive. If I want to be particularly successful on Tinder, I’d put up a representation of my face, but I’d make it bilaterally symmetrical so I could duplicate maybe the left side of my face. I’d make my skin yellower. Yeah, make your skin a little yellower. You can do it. The last most recent research on the yellowness thing, gruntiness thing, is people did experiments where they put people on different diets and they measure their, take their facial picture before the experiment, and six weeks after, in six weeks, you can improve your facial attractiveness by carotenoid, including more carotenoid in your diet. So it can be pretty quick. And students love this when we talk about it in class, of course. I’m telling them how to get prettier in a hurry. All right, so let’s move to the next major topic. I came across your work on parasite stress theory a few years ago. I started to get interest. There was a burgeoning literature on the role of disgust in political idiocy. And I ran across your parasite stress theory. And so, and you were looking to begin with that, the relationship between parasite stress and values. And so maybe we could delve first of all into, well, what parasite stress is and how you would study that in relationship to value and why you would ever think to do that, because it’s by no means obvious. Okay, so the parasite stress, what we call the parasite stress theory of values. We also call it the parasite stress theory of sociality is a scientific theory about how people get their values. So the causes of people’s values. And the theory is a theory about both proximate causation and ultimate causation. So in biology, there are two general categories of causation, proximate and ultimate. Proximate causation has to do with causes of something that occurred during the lifetime of the animal. Events during the lifetime that cause whatever effect you’re looking at. That’s proximate causes. Ultimate causation has to do with causes in the deep time past, evolutionary past. So ultimate equal evolutionary, proximate equal causes during the lifetime of the individual. And this theory of parasite stress theory of values is both proximate ultimate theory about how we get our causes. So let’s start with the proximate level of causation of our values. And what I mean by values. So that’s kind of a big topic. If you look at the history of research on values, it is very large. And almost unbounded, what psychologists have called values. So value would be something like rank order preference, if we’re going to define value itself, right? Because we have to choose between things. And we choose those things. Yeah, that’s value. We were talking about the value people place on looking at one face versus another. That’s a value. That’s a preference. Right. And they’ll donate more attentional resources to high value faces because attention is a marker of value. Right. But we can talk about what psychologists have called values and the study of values. And that’s a big, big area of research, values research. And the history of it all is really, really cool. But anyway, we can sort of bound this discussion of values in what political scientists refer to as values. And what they refer to as values is the political dimension of highly conservative to highly liberal. So it’s a continuum of values. And you can measure a person’s values. They’ve worked hard to come up with ways to measure a person’s values. You measure a person’s values, and you can put that person on that continuum somewhere. Everybody can be put on that continuum from psychometric procedure, questionnaires. So the political scientists have done values that way. Cross-cultural psychologists have done values in terms of collectivism and individualism, that dimension with high collectivism being low individualism, high individualism being low collectivism. And it turns out if you look at these two dimensions, so one from psychology, collectivism, individualism, one from political scientists, conservatism, liberalism, they correspond. So high collectivism is conservatism. High liberalism is individualism. And so you can think about what I’m talking about in terms of core values by those two dimensions, conservatism, liberalism, and collectivism, individualism. And basically, as I show, they are as we show, that those dimensions are very, very similar, if not identical. Would you take them apart a little bit and talk about collectivism, conservatism, and liberalism, individualism, so everybody knows? I will indeed. Yeah. Excellent. Yeah. So you measure these, a person’s collectivism said differently, you measure his or her individualism. And what you’re measuring, so let’s start first with conservatism. So a conservative person has sub components of this value system. So the person has beliefs, importantly, in traditional things, traditional things, and parochial things, local. Also, the person is relatively xenophobic. If conservative people are relatively xenophobic, and xenophobia is fear, dislike, avoidance of stuff on the outside, foreigners, people, new ideas. So xenophobia has a neophobia component. Neophobia means phobia about the new. So you like traditional stuff. You don’t like new, you don’t like foreign, but that’s a xenophobia component. So conservatives have the xenophobia, the traditionalism, parochialism. They also are high in ethnocentrism. Ethnocentrism is a preference for people like you, your in group. Define your in group that starts with your nuclear family, but then extends to an extended family, and others with like values, like you. So that’s your ethnocentric component. And another component of conservatism is liking to just stay home. So, Philip Patrick, love of where you’re born, you stay there your whole life, and so forth. They’re highly conservative in highly conservative cultures. You don’t move much. So that’s conservatism. And then the antipole of those values really characterizes individualism or liberalism. So instead of xenophobic, you’re xenophilic. You like people that are different from you. You’re comfortable with other kinds of people, even if they have different values, even if they have a different color, even if they believe differently. You’re more comfortable with those than you are if you’re conservative. And ethnocentric, esocentrism is low under individualism, and more nuclear family oriented than extended family oriented. And your in group is really composed of people with all kinds of different beliefs, and maybe colors, and so forth, backgrounds, as an individualist or liberal. And you’re more prone to moving around. Frontier spirit, movement, and adventure, and going new places is a good idea. You got a passport if you’re liberal. So those are some big differences between the two poles. And how much is that, do you suppose, is it preference for familiarity versus preference for novelty? Is that at the core? No, that’s at the core. That’s part of the neophobia. You could put that under the neophobia. So the fear, avoidance, dislike of new. And that can be new ideas. It can be new types of folks. It can be new discussions. All those kinds of things are avoided. And it just, most generally, it characterizes outside. OK, so let me ask you a really specific question about that. Because you could think about that two ways. You could think about that as avoidance of the unfamiliar and dislike of the unfamiliar. Or you could think about it as marked preference for the familiar. And then on the other side, you could think about it as marked preference for the novel. Is it against something or for something? Or is it both on both sides? It’s both. The against can go all the way to hate. You know, under high xenophobia, hate. And even, you know, we get into how conservatism and traditional societies and so forth promotes intergroup aggression, warfare. So the point where you not only hate those outsiders, you want to kill them. And so you have both components there. The out group, the avoidance, as well as the interest in socializing with people that are like you. OK, OK. So we’ve got the values dimensions nailed down. And so on to the parasite stress. Yeah. So when you start looking at conservatism, let’s start there. The connections to parasites jumped out at us. And let me try to explain. So with xenophobia, OK, you want to avoid those people over there that are different from you. OK, and that’s that’s tied to a very fundamental part of host parasite co-evolution. So the way host parasite co-evolution works is that it’s it’s ongoing and it’s antagonistic. And the parasite is trying to evolve to eat the host. The host is evolving defenses against the parasite. And that continues forever. You never get out of your host parasite co-evolution any race. So you get this co-evolution race between host and parasites. And much, much, much research shows how localized those co-evolution races are geographically localized. So you get different strains of TB in different neighborhoods and a big city in Morocco, for example. It’s geographically very, very localized. These host parasite coalition races, which means that locally you’re relatively immune to the parasites, but the parasites on the outside and those people on the outside in the outgroups, those parasites, you’re not immune to. So that’s why you have xenophobia. It is a way to avoid foreign parasites that you’re not evolved to deal with immunologically. That’s a xenophobia component. So that’s contamination. It’s avoidance of contamination. Right. And yeah, from parasites that you’re not immune to because you’re relatively immune to the local and you’re safe with people that are just like you, okay, the local people, because they’ve got immunity like yours and yours is relatively good against the local parasites, but not the foreign parasites because of this localization of the host parasite coalition. Right. And so you’re saying that you don’t have to go very far away before you get yourself in trouble. No. All these new strains of COVID popping up, there are going to be lots and lots and lots and lots and lots of strains. And you hear about some of the strains now, they’re eight or 10 or something like that, but they’re popping up and there are more of them. The surveillance on this new strains is pretty limited so far. They haven’t done a lot of that because they’ve been doing other things with the pandemic. But still you get that occurring with the COVID too, this localization of the strains. There’s a South African strain and so forth, so on UK strain, all that. So you don’t have to go very far for the localization of the immunity you have to not work so well. And that’s where the philipatry comes in too. So philipatry, you just stay home. You stay home, you interact with people that are immunologically like you and therefore are safe, relatively safe, rather than dispersing to interact with foreigners and the habitats that may contain these parasites you’re not adapted to. So that’s the philipatry component. The ethnocentric component is related to, so when the diseases come, you want to have a lot of local social support. So you have all these ties with extended family and so forth. That’s your social support. And in ethnographic societies, traditional societies, anthropologists have done a lot of research on how important it is to have kin that will help you when you get sick. That’s the only way you can make it. You have kin and kin and friends locally that help you. That’s the ethnocentric component. So if there’s a high probability of illness occurring, then you’re more dependent in reality on your closest network, your kin and your friends, your close friends. Exactly. The higher the parasite stress is in a region, the more likely those parasites are going to come eventually. And so you’ve got to have that social support that’s important for dealing and getting through you and your family, getting through the parasite crunch. So that’s why the ethnocentrism, philipatry, and xenophobia components. And those have the component, another part, subparts of that we talked about, openness to new experiences and all that that’s part of really neophobia. Right. So we, okay, so there’s a personality. So I got a couple of specific questions about that for you. So the best predictors of conservatism from a personality perspective are openness to experience, low, and one sub aspect or one aspect of conscientiousness, which is orderliness. Now, I noticed in your research, you looked at extroversion and openness together. And you saw that the more collectivist slash conservative types who are protecting themselves according to parasite stress theory from contamination are likely to be more introverted and lower in openness. And that means less exploratory in general, because those two things together seem to maybe make up exploratory behavior. But there is good personality data showing that the orderly part of conscientiousness is also a predictor of conservatism. And that I don’t know if I don’t know if there’s been any data because that’s a more micro analysis in relation to conscientiousness. Nobody’s looked at that component. But absolutely orderliness is very fundamental to conservatism. You want order. Disorder is chaos from the standpoint of a conservative mind. You know, you want order in everything. Yeah. And chaos is see, I’ve thought, and this is interesting too, because maybe we could talk a little bit about the emotions that are elicited here. So for the longest time, I was, I had been thinking about the conservative collectivist viewpoint in relationship to novelty in two elements, two manners. One is that the more conservative mind doesn’t get as much of a positive emotional kick out of novelty and exploration. Right. Because that’s fundamentally motivating if you have the personality type that’s associated with exploratory behavior. But then there’s this idea of phobia too, like neophobia. But you know, conservatives aren’t higher in neuroticism. And so, and that, and that’s really a striking finding because if anything, it turns out that at least under some conditions, liberals seem to be higher in trait neuroticism. But there’s a role of disgust that seems to be under examined. And is it, is it, is the neophobia a consequence of fear or is it a consequence of disgust, which seems more tightly associated with immunity as opposed to say fear? Yeah. Well, you, I mean, you know, you can, you can get prejudice. Toward an out group that has fear components and disgust components. I mean, you can be absolutely disgusted, you know, how the conservative person who has to interact with an out group will might even have to discuss face, how to discuss it. But it’s also. I mean, I think you see that with food, for example. Yeah, right. You get it with food or, you know, any, any kind of pathogen threat can evoke disgust, just an emotion of disgust in, you know, in a person. And the more conservative they are, the more likely to get the actual disgust reaction. Yeah. Well, and disgust, you know, I. Moral violation, food, rotten food, dirty toilet, all that stuff. Yeah. So that, that some account, like people have struggled for a long time to make sense of dietary prohibitions in religious contexts, for example. And, and I mean, if you have dietary restrictions and markers for in-group identification, that’s a good way of deciding or of determining consistently who’s on your side and also marking who’s on the other side. Yeah. All kinds of things come into play to indicate boundary between in-group. Boundary. Now. Well, okay. So when I was looking at thinking about the relationship, you know, there’s, there’s five basic personality dimensions and 10 aspects. And so, but only two of them really, really strongly predict political affiliation and that’s openness. So high openness is liberalism and, and, and orderliness, which is less powerful predictor. But so the conservatives are low in openness and high in orderliness. And I thought why in the world do those two uncorrelated personality predictors co-vary to predict political belief? And then I thought over a number of years that it has to be, it has to do with borders. It’s the fundamental political question is the conservative likes thick borders between everything and the liberal wants thin borders and the liberal wants thin borders because their niche is the locale where information is transferred. And, but the, the, the, the, the counter tendency is the conservative tendency to say, yeah, but if you’re aware of the information is going to be transferred because the borders are thinned, you’re probably going to get sick and die. And they’re both right. Yeah. Seem reasonable. Yeah. Right. In terms of what is sometimes the conservatives are right that you’re going to die. If you get, if you expose yourself to what’s new and sometimes the liberals are right in that you need what’s new to renew you. Right. Well, these, these values that we acquire are very strategic and they’re, you know, they’re suitable for our understanding of the culture that we live in. They’re suitable for that. They’re optimal for that. So if you grow up, we haven’t really talked about the evidence yet behind the parasitization theory, but and that’ll get that your comments get me into that. So we looked at, we looked at the theory in relation to what it predicts to test it. So it predicts that the, you know, if you take measures of parasite stress across the world, countries or states in the United States or whatever, that that will correspond to conservative or collective displays measured by, measured by political scientists, these measures and put in the literature for countries and states measures of psychologists, of individualism, collectivism put into the literature. So we pull those data and look for the predictive relationship between parasite stress and conservatism and liberalism and found what we expected and strongly so. The more parasites, the more conservative. Said differently, the more parasites, the more collectivists. And so does that broadly mean the more infectious diseases? Yes. So yeah, more, there’s two ways basically we’ve measured or several ways now we’ve measured infectious disease levels. So by parasite, I mean, any infectious agent, it doesn’t mean just intestinal worms or something as any infectious agent. So virus, bacterium, worms, whatever level of parasites you’re talking about is a parasite. Infectious disease, synonymous with infectious disease. So you can take number of infectious diseases per country, for example. You can take number of infectious diseases per state for the US. Or you can take the rate of infection. So the proportion of the population that has each of these infectious diseases in an area. So either number of infectious diseases or the prevalence of the infectious diseases. And either of those very strongly and similarly predicts the values with more infectious diseases, more conservatism, that is more collectivism, the fewer infectious diseases, the more liberalism. That’s done on just the geographic level. But then, and we did all that initially. And then others came along quickly, actually, once it got started. And it’s still really blooming out there, all the research on the parasite stress theory base done by people all over the world now. But people started doing it at the individual level. So you bring a person into the lab and you show them cues of immediate parasite danger. So these are just like a slide show with disease cues in it. So dirty toilet, a person with skin pox, a person sneezing, those kinds of cues. So they see these slides. And then you measure their values before and after seeing the slides. And you have an immediate effect. Amazing. Immediate effect. So let me talk about the power of these relationships. So if I remember correctly, some of the data that your team generated showed that the correlation between infectious disease prevalence, so parasite stress, and conservatism was as high as 0.7. So staggering, unprecedented strength. That’s stronger than the relationship between general cognitive ability. Or it’s as strong as the relationship between general cognitive ability and learning, which is the strongest association I’ve ever seen in social sciences. Yeah, yeah, yeah. We get some big effects. I mean, they’re very in terms of what particular prediction we’re looking at. And we’ve looked across so many domains of human life that there’s variation in effect size. But yeah, some of these effects are tremendous. And of course, we do through standard statistical procedure, we do controls to potential confounders in all these analyses. So that’s it. You do the regional stuff with countries of the world, states of the United States in relation to values and parasite level. But then this stuff coming along with looking at individuals really is nice too, because you’ve got the same patterns in the regional level and the individual level. Right. So we should take that apart a little bit. So the problem with comparing nations is there’s lots of differences between nations that might be correlated with parasites. But then if you go to the state by state level within a country, you control for lots of those variations. You have, you have. And also in your analysis itself, you do statistical controls of things that potentially could be problematic confounds, whether you’re looking at between countries or between states. So we have data from all those levels. Some of the more recent stuff that’s coming out now, people are doing, they did a lot with the slideshow that I mentioned. There were 10 slides that reliably will evoke greater conservatism. But then now they’re looking at showing people like a short story about COVID. COVID is real serious in your neighborhood or something like that. And that does it too. So do you think there’ll be a swing towards conservative political belief across the world because of this pandemic? Will that shape the political beliefs of a, and is there a crucial period for that to be shaped? So for example, will this have a bigger effect on say, 14 to 16 year olds or 16 to 18 year olds who are catalyzing their identity? Would you, would there be a cohort that would be more? That’s a really interesting point. And I’ve thought a lot about it. We don’t, there’s no, there’s no, there’s no data on that now. So if you, I mean, the way that you could empirically attack such a thing would be to look at people of different ages in relation to like the effect of these experiments on them. Do you get a bigger effect size when you show slides, disease slides to one age group versus another? Yeah, or would it last longer? We don’t know how long it lasts either. That research surprisingly has not been done. You bring people into the lab. And you show them these slides and you get the effect. Also, one nuance of that is if you measure the, what we call the perceived vulnerability to disease, that’s a 14 item questionnaire that’s validated and measures a person’s concern about infectious disease. And that’s an individually variable thing. More conservative people are the higher their score on that, of course, and worry about infectious disease. So people that are high on this going into the experiment show a bigger effect when they see the slides. They shift more in terms of degree of conservatism. Do you know if there’s any effects of personality on that? So if that hadn’t been looked at, hasn’t been done yet, but it would, there would be some covariance there because the people that are high and worry about infectious disease are basically conservative people. So they’re going to have less openness to new things and more introversion and all that kind of stuff. So when I first came across your parasite stress hypothesis, I was reading a fair bit of the literature on disgust generated, a fair bit of it, by Jonathan Height and his research team, because he was one of the first psychologists to look at disgust as an independent emotion. But I was reading a book called Hitler’s Table Talk, which was a collection of his spontaneous utterances at meal times collected over about three years. And it really affected my reading of it because the number of times that he referred, that he used parasite metaphors really stuck in my mind. And I started to look at all of the Nazi propaganda from before the Second World War in terms of parasite stress hypothesis, especially after I also realized that Hitler’s extermination campaign arguably had its origins in public health policy because they started out with tuberculosis interventions, and then they went to clean up the mental hospitals and so on. And Hitler went on a factory cleanup binge, essentially, after coming to power. And they used a variant of zyklon gas as an insecticide in the factory cleanups. So this was all quite terrifying reading what you were writing and reading this at the same time. And I don’t know what you, I mean, I’m going to ask you to comment about that, what you think about that. But the metaphor for parasites, that’s a fundamental metaphor that the Germans, the Nazis, tend to view themselves as under assault by parasites. Mussolini was the same way. So you said Mussolini was the same way. Exactly the same way. He was just a replica or Hitler, a replica of him. Mussolini was, you know, his fascist dictator of Italy when Italy was fascist, and Hitler, fascist leader of Nazi fascism. But Mussolini, he, for example, outlawed handshaking in Italy. He thought it was the most disgusting thing to touch a person’s hand. He was as much germaphobic as Hitler. And Hitler bathed four times a day. That’s still going on in some parts of the world. And these 30 minute showers in the Middle East, people talk about, where you get the highly conservative people that really clean up. But with regard to fascism, I’ve been very interested in fascism, of course, because it’s over there on the extreme pole of conservative in things, you know. It’s got all the components of conservatism in writ large. And so I’ve been interested in the origin of fascism in Germany and in Italy, and Japan about the same time. The three big fascisms have been some other fascisms, too. But a recent study, you’ll be interested to know, has looked at infectious disease in German regions, cities, in relation to voting for Nazi, for Hitler’s party, National Socialist Party. And the more the more the way it works is so he had his data from 1918 to 1920. The number of Spanish flu cases in all of your I never thought about Spanish flu as a contributor, because that came right after World War One, of course. And yeah, right after World War One was one of the things that devastated and already devastated Germany. Yeah, in the world in general. Germany was really hit hard by the Spanish flu, as Italy was, too. And what this guy did, he got data, there’s a data collection managed by the University of Michigan on the data from Third Reich. And before the Third Reich became officially a Third Reich in Germany. And these data include the number of cases of death due to Spanish flu in all these German cities. Also, they got number of deaths from plague and tuberculosis and so forth, too. Tuberculosis was still a big problem by that point, too. It wasn’t just Spanish flu, but Spanish flu was the main killer. But tuberculosis was probably number two. Plague wasn’t a big deal by that point. So these data have number of votes in these different cities for the Nazi Party. They had the number of votes for the Communist Party and number of votes for various things. So the Communist Party was considered extremist then, as was the Nazi Party. And the votes are from the years 1930 to 1933, I think. So the critical years for the rise of really Nazism to get big there. And the more people dying from the Spanish flu in 1918 to 1920 in a city, the greater the vote for the Nazi Party in 1930 to 1933. So that’s a connection that was of interest to me. And this paper has recently appeared. Any idea about the size of the relationship? And what about economic? Are there confounds of economic well-being in the cities? Very important. He controlled, he was able to control through the same data set for employment in those cities and for average wages in those cities. Two variables related to economic state. That’s the traditional thing. Historians will tell you, well, the Germans were so economically distraught that they bought this stuff, you know. But the parasite stress theory values adds a new mirror here, I think, for fascism. In Italy, I’ve searched and searched for data on flu death in Italy. But I don’t think there’s going to be anything like it. For some reason, a third Reich collected lots and lots of data. And somehow University of Michigan, I don’t know the history of the acquisition by the University of Michigan of these data, but it is a reliable data source that is used now in sociological research. Now, you’ve studied other elements of parasite stress theory too. It’s relationship with altruism, relationship with human cognitive abilities. Yeah. Yeah. So, yeah, we did study of IQ in relation to parasite stress across the world and across the states in the US, and that worked out very well. The thinking was simply that if you’ve got, you know, you think about that human immune system, it is tremendous. It’s everywhere in the body. And it’s very, very costly system in terms of the energy and in terms of tissue to make and maintain this immune system. Humans have this huge brain too, very sophisticated nervous system that is very costly. So we assumed that these two components of the body immune system and nervous system would trade off. And so under high infectious disease, you got to make a good immune system or you’re going to die. But that’s going to cost you in terms of neural development and so forth. So we predicted that more infectious disease, lower IQ. Predicted it for across regions of the world, countries and states. And so we went to the IQ literature, which is massive. That’s a big topic in psychology, as you know, study of IQ. And there were data for essentially all the countries of the world. And there were data for the states. And we pulled those and looked at the predictions and the predictions were met for both across national predictions about 0.8 between parasite stress and IQ. More parasites, lower IQ, about 0.8. For the US, it’s about 0.7 US states. Within states? Yeah, between the 50 states. You take average IQ. Okay, so let’s pull back just a bit for everybody. It’s important for everyone who’s listening to realize just how important a role infectious disease actually plays in the shaping of human evolution, cultural evolution included. So for example, there are estimates, correct me if I’m wrong, Dr. Thornhill, but there are estimates that 90 to 95 percent of the native inhabitants of North and South America died as a consequence of contact with Europeans because of the transmission of measles, smallpox, and mumps primarily. Although they were also prone to many other diseases that were brought in by the Europeans who had lived in tight packed cities, often with animals as close companions, had had, what would you say, exposure to a wide variety of extremely toxic diseases, developed immunity, but then brought those diseases to the new world and basically decimated the entire population. So this is a non-trivial event by any standard. The Europeans, by the time they started moving out of Europe into the new world, the Europeans, I mean, they had all their diseases, but they had relative immunity to lots of respiratory diseases, turns out. And so they brought all that stuff over here and killed most of the native new world people. Yeah, most of them. I had read that when the pilgrims hit Plymouth, the natives were desperate to see them because they had lost so many people they couldn’t harvest their crops. Yeah. Yeah, it was a mess and continued to be a mess a long time. Right. So when isolated populations of human beings have come into contact in the past, the upside is the trading of cultural resources, essentially. And that can be a tremendous upside, but the downside is the exchange of infectious diseases. That’s right. And we’re caught between those two, well, those two, an opportunity and a catastrophe, which present themselves simultaneously. Yes, openness and just liberalism is great in terms of its benefits. You’ve got interaction with lots of different kind of people. You get a bigger social network, got a bigger mating pool. You don’t care if they’re different from you. You want to interact with them. You can innovate out of catastrophe. Yeah. New ideas, new ideas, innovations coming from the outside that you can use locally. But that only work under low infectious disease, because we get high infectious disease, all that outgroup contact interaction. Okay. Yeah. Well, that’s exactly what we’ve seen in the last two, year and a half, too. Yes, absolutely. So we’re right in the middle of it. We’re right in the middle of it. And the mortality, the human mortality from infectious disease before the pandemic was still greater than any other measured source. There’s a recent work that’s looked at. You can just sort of summarize it this way. You can look at genes that play known roles in human life. So there are genes associated with immunity. And those have been described by immunologists, which genes are involved. There are genes involved in diet, the genes involved in digesting protein, and all that kind of stuff. All these gene functions are known. If you then you look at where in the human genome, there’s the most turnover of new alleles, new genes. Those are genes that are evolutionarily very active. It turns out that the immunity genes are the evolutionary hot spots in the human genome. And that says there’s more mortality from infectious disease than from other measured problems that humans face. Most mortality still is from infectious disease. That was done at 50 sites, human sites throughout the world. So that provides evidence that that’s actually the worst threat facing us. The worst threat. Constantly. Hence its powerful effect on such things as values. Absolutely. It’s the main mortality factor. And if you look at the anthropological evidence about the importance of infectious disease versus other things, there’s a lot of evidence for that. I did a nice review recently that some people did. But infectious disease is the main killer of infants and older children in the ethnographic records of traditional societies. Infectious disease is the big one. Next is infanticide. That’s number two. Parents kill their kids strategically because they can’t raise them under resource limitation or the kids are sick or whatever. Infanticide is very common. That’s number two. But infectious disease is the main killer. So, okay. So here’s some radical ideas, I suppose, because reading all this, learning this. Okay, before we go there, let’s do one other thing. Main objections to the theory, practical and empirical. What’s what I read a paper recently, and I’m afraid I can’t cite it in detail, but it’ll serve as an example, claiming that with proper control for technological development, the effect of parasite stress on political belief vanished. Now you cite many, many papers in your books and in your papers. So I’m by no means saying that this is a canonical study, but it’s very useful. This is a very, very, very, very provocative theory. I mean, it upends in some sense. My sense when I first encountered it was that it upends almost everything we think about politically. And so it, and it’s a very, very, very, very, very, very, very provocative theory. And so it, and what’s the saying that that extraordinary claims require extraordinary evidence. We’ve got to look at the counter evidence too. So what do you think are the main weaknesses of the idea as far as you’re concerned? And how have you addressed them and have they been successfully addressed? Yeah, we had, we had, we’ve addressed them as they have come out and the parasite stress theory of values has gotten, when it first came out, it got so much attention that that attracted a lot of people to try to falsify it, you know, and that’s the way that works in science. Yeah, thank God. We went through that. We went through that phase and now all the research is looking at very interesting spin-offs in productive ways of the parasite stress theory and no criticisms have come out recently, but the kind of thing you’re talking about where, you know, it’s really modernity, modern things and so forth that controls our bed. That’s an old idea in the literature that, you know, basically people just get more modern, they get more liberal and so forth. And we take that on in a number of ways. And the one way I’d like to, you might be interested in, we look at the cultural and social revolution of the 60s and 70s in the West. So what happened, and I was there, you had a liberalization of values, basically, it’s the bottom line, but you had more, you know, more, you know, the women’s movement started then, there was the sexual revolution, same time. Right. Which aids put a terrible crimp in? Another infectious agent? Yeah. And ethnic groups, minority groups that had been ostracized and so forth got more attention, positive attention. There was democratization of law, voter laws and all that change. So it was more than just people talk about that time as the sexual revolution time, 60s and 70s, but really it was a much broader social revolution involving human rights, increasing human rights and liberties, basically liberalization. So what the hell happened? Well, here’s what happened. It was infectious disease changes that began in the 20s that led to all these liberals in the West in the 60s and 70s. And these infectious disease changes are well done. To the control of infectious diseases like malaria? Yeah. Well, yeah, bigger than that. It started out in 1920 with chlorinated water. That started in the West. We’re talking about the West. And the rest of the world didn’t change. They didn’t go through the social revolution. Many places in the world still haven’t because of disease levels are high, all of Africa, basically, much of Asia. But 1920s chlorinated water started in the West and quickly spread throughout the Western world. By the Western world, I mean US, Canada, Western Europe, Australia, New Zealand, those places. So chlorinated water and that knocked out lots and lots of infectious disease, put a little chlorine in public water. Also in the 20s began some systematic garbage collection before people just threw the garbage out in the alley. Sewage treatment plants started then too. And there was more indoor plumbing starting in the 20s. Now let’s jump to the 40s. 40s big, big changes with regard to emancipation from parasites. Child vaccination programs began in the 40s. Also antibiotics, first good antibiotics right after World War II, 1945 in the 40s. So this was really by that point a new world in terms of lowered infectious disease compared to the world that all generations of humans had experienced in the West prior to those 20s and 40s. There was some antibiotics in the 30s, but sulfur drugs and so forth, but they had terrible side effects. So the real good antibiotics didn’t come along until the 40s and broad spectrum kind of antibiotics. And of course that spread so rapidly that the use of antibiotics that quickly saw resistance to antibiotics popping up, you know, the evolution of resistance and parasites. Which is a serious problem we have now because we have diseases that are resistant to almost all the broad spectrum. Absolutely. Even in combination, that’s a looming catastrophe which we should obviously pay attention to. Right. Arms race between the parasites and the drug companies now with that. So up to the 40s and then also in the 40s you had insecticides coming along. Good insecticides, chlorinated hydrocarbons and organophosphate insecticides that kill pest species, including mosquitoes. So vectors, important vectors of disease in the West, mosquitoes, so they knocked out malaria, knocked out yellow fever with that. And so all that was going on to emancipate people. And then the generation two or two later, you get the rise of liberalism throughout the West. So all these liberal young people growing up in a relatively disease-free environment by all these health interventions became the hippies and so forth. They were healthy enough to be free. Yeah. And so that does really raise the question again of what COVID, this COVID pandemic and the lockdown is going to do to the political temperament of the West or the world for that matter. But it’s a particular change in the West because we’re not accustomed to this sort of thing anymore. So it’s so interesting because of course I’ve thought of the liberalism revolution being a secondary derivative of birth control pill, which is a biological revolution of immense magnitude. But I hadn’t ever considered in depth. Yeah. Even after reading your book. I mean, the use of birth control and all that by women, that takes some willingness to try new things. Right. Well, that’s it. That might be dependent itself on… That’s a way away from tradition, taking birth control. So there’s another perverse implication of the theory that you’ve developed too, which is that conservatism insistence upon hygiene and disease prevention is a precondition for liberalism. Yeah. Successful, right? So it’s in some sense, the conservatives are battling off the disease so that people can stay healthy. But the consequence of that is as soon as that they’re healthy, they become liberal. Yeah. Yeah. God, isn’t that something? Yeah. Well, here’s the thing. You can look at it like this. So if you’ve got high conservatism in a place, then those conservatives are doing things that promote… Well, they’re not using modern technology. They’re not open to new ideas. They’re not open to science and all that. So those are attitudes that help the infectious disease, really. Right. Right. Right. Right. So they’re reliance on traditional… That’s right. Traditionalism is also an impediment, tremendous impediment. Yeah. It reduces their contact immediately. So it works against them that way. I mean, if you’re not pro-science and open to new ideas and innovations and all that kind of stuff, that has tremendous limitations. And so you don’t even put in septic tanks or chlorinate the water. Okay. So another… You don’t get a vaccination. Right. Well, okay. So let’s talk about two things then. One is I’ve been struck. Tell me what you think about this. COVID has become a politicized issue in Canada and in the US, but it doesn’t seem to have happened the way you might’ve predicted if you were relying on parasite stress theory, because it seems to be that the conservative types are the ones who are objecting most strenuously to the lockdowns and to the inoculations, whereas the liberal types, I mean, and maybe I’m wrong about this, but seem to be more in favor of the restrictions of movement and so on. And that actually, I can’t get my head around that exactly. Yeah. No, you’re right. That is the pattern and that’s been studied now. And there’s some papers on it. And here’s the way, here’s what’s going on, I think. In the US in particular, the conservative government at the time when COVID was getting off the ground, the Trump administration was very negative about COVID. I mean, he called it a hoax and all that, didn’t believe it, and no problem. And so that is the authority. We need to talk about authoritarianism because this is where it comes in. You have the king, Donald Trump, saying that it’s no problem, this disease is no problem, and it’s just going to go away as a hoax and all that kind of stuff. And that is the word from God, basically, to highly liberal, highly conservative people. And that’s the way authoritarianism works. People that are highly authoritarian, and that’s conservatives, there’s a lot of evidence there, authoritarianism is very highly correlated with conservatism, in fact, a component of it. The more authoritarian the people are, the more likely they will follow these guys that they label as their leader. And to the point that they’ll follow them anywhere, they’ll follow them off a cliff, basically, as they did in Germany, as they did in Italy, and as they did in the United States during this COVID thing. So you believe that what happened was that the evidence that there was, in fact, a dangerous epidemic was rendered non-credible, and so conservative tendency to prevent the disease didn’t kick in? That’s right, exactly. And you think that’s a good enough? It was the authoritarianism that conservatives are carrying. And had Trump acted another way, you know, said, this disease is really important, I want you folks to wear a mask and be careful in distance, and all that kind of stuff, then there would have been a different outcome, because that would have been the authority message. So it’s one element of authoritarianism slash conservatism interfering with another. That’s right. Okay. Parasite stress and sex. Yeah. There’s been some look at values in relation to sex. So conservatism, conservatives are conservative. So there’s old studies that, there’s one paper I should send you, it’s you’ve got all kinds of correlations in there with everything under the sun in relation to conservatism and liberalism. But, you know, interest in different positions, copulatory positions and all that. The conservatives more likely just stick to the missionary style, and whereas the liberals are more adventurous with regard to positions. And is there a relationship between adventurousness in sexual position and the risk of transmitting sexually transmitted diseases? Don’t know. I haven’t seen anything on that particular thing. But, you know, liberals are more interested in, be more interested in partners that are in different ethnic groups. I mean, that’s been studied. You don’t limit your sexual interests just to your in group. If you’re liberal, you’re happy with people of different color and different backgrounds and all that kind of stuff as sex partners. So those kinds of things have been done with regard to sexual behavior. We did the variable social sexual orientation. It’s a variable. It’s validated in psychology, and it measures really a person’s attitude about promiscuity or sex without commitment. You call it sex without commitment. And that varies among individuals, their attitude about sex without commitment. And we looked in their data on, I think it was 120 countries measures. So we took those data and looked at them in relation to parasite stress and values. And the more parasites, the less interest that women show in non-committal sex. So the more parasites. And that’s mediated, I presume, by a cultural response to the presence of the parasites. Right. That’s conservatism. Yeah. And I will have any studies being done that are analogous to the political studies where people are shown images that are reminiscent of parasitic presence and then asked about their sexual preferences with regards to monogamy or uncommitted relationships. No, that hadn’t been done. No, that hadn’t been done. Now, there’s a PhD thesis for someone. Yeah. We just took the SOI data, sexual orientation inventory data, for men and women across these countries and looked at it in relation to parasite stress and values. And as I mentioned, as infectious disease increases, women show more restriction. And it’s women specifically? Women specifically. The effect for men is not reliable. This is not very big and probably not even reliable, statistically significant. But for women, it’s highly significant. The more parasites, the more restricted women are. And that goes along with conservatism. So conservatism, there’s a sexual purity and protect the jewels kind of attitude that is instilled by conservative culture in women. So in women, well, so there’s a question. You know, it’s a double standard. Well, when you get parasite stress increasing, then is the conservative proclivity manifested to begin with in the women and then spread to the men? Because they’re more primarily concerned, let’s say, with sexual contamination. I mean, the role of the genders in determining the men are changing. The men are changing in other components. So the men are hot to trot regardless. Well, that’s what I was thinking. Yeah. But the men are changing in terms of becoming more xenophilic and ethnocentric and those kinds of things. So the sexual changes don’t drive the rest of it? No. Okay. Because I mean, changes in sexual behavior often drive changes in other phenomena. It can be important. Yeah. You also wrote right about parasite stress and religiosity. Yeah, we did a big study of that looking at religion scholars, looking at their data on commitment and participation of people in religion across basically all the countries of the world. And we had state data to US state data on participation and commitment of people and predicting that more parasites, more religiosity measured either as commitment or participation and more conservatism, of course, more religiosity. That’s well known already. More conservative people. And those would be traditional markers of religiosity, like church attendance, such as church attendance rather than spirituality per se. A number of times a month you go to church and stated commitment that you have. Do you believe in the local religion, that kind of thing? This religion scholars have done a good job and then published all that in the literature. So you can pull their data and then look at it in relation to parasite stress, more parasites, more religious people are. And we expected it from following ideas that it was known that religiosity is very tightly correlated with conservatism before that had been shown by lots of folks in the past. But religiosity has some couple of parts to it that were of interest to us from the standpoint of the parasite stress theory. One is the boundary issue that religions often show. So in fact, religion scholars define religions in terms of boundary. So this group over here believes in this God, the group over here believes in this God or gods and so forth. So those are boundary markers. Yes. And so the boundary would be like a xenophobic kind of function, you know, to end group out group of separation. The other part of religiosity that was an interest from the standpoint of the parasite stress theory is the ethnocentric part. So you get that in group binding with your with your colleagues at church and so forth. That can be extremely strong. And so that we looked at it and found that basically a new theory of religion that more parasites, more religiosity across countries, the world and states. And what sort of effect size is that? Those I don’t remember offhand, big effects. I mean, it was published in a major brain and behavioral sciences, major, you know, top, top tier journal. But again, you could, you know, back to your earlier question about showing people these immediate parasite threats, the slides or some other way that they’re manipulating that now they’re doing all kinds of things with that. And see if people get leaving God more or something like that immediately. That would be cool. Yes. Yes, it would be. And you change a person’s belief in spirits by by that. Well, you also wonder too, if you know, I’m just thinking here, ideas are just flashing through my mind about beliefs in spirit to begin with, because he belief in spirit causing illness, for example, is sort of an early analog of a disease theory. You know, yeah, yeah, I mean, people are, there’s a study that I can’t remember exactly what it is better on my pile over here. The claims that the fundamental belief in spirit that the fundamental belief we have in a spiritual world really boils down to spirits as diseases, disease causing entities, they are invisible agents that are invisible. But you can transmit them to yes, evil eye and all this other stuff in cultures that suggest transmission of this of the spirit. And of course, before the germ theory, before germs were known parasites were known to cause disease, it was all invisible. So spirits feel that and which is, you know, as as which is as channels for the evil that these spirits have, that’s part of it too, and the Inquisition and so forth and so on. All this real cool stuff. And everything that’s unknown. Right? Because they well that and it boils down to a disease. Right, right, right. They were right. The disease was killing everybody, most of the people anyway, you know. So yeah. Well, you know, that was all actually too interesting, I guess I’d like to close with this. So you’ve been studying this a long time. And it’s very unexpected. It’s a very unexpected theory, I would say, what, how has knowing this how is studying this changed the way you look at society and people and political dynamics, I mean, you’re in this position, I’ve only been digesting the material you’ve been producing for about five years, I would say maybe maybe 10. Yeah, it hasn’t permeated my thought system entirely. But you’ve been wrestling this with this for three decades, two decades anyways. So in a sense all my life, let me explain, I was born and raised in the old South, I was born and raised in the old South, heart of Dixie, Alabama. So I was born into a culture that hadn’t really changed in 100 years, except they had cars and stuff. But ideologically, there’s been no change since the Civil War. Very conservative place. And for reasons I may, I think about a lot, how come I came out of it liberal rather than conservative. I would say, I was found what these people were doing day in, day out, I see your face all the time if you live in a conservative culture, the inhumanity. And why aren’t they doing that? And what’s wrong with you people, that kind of thing. And then finally, I just decided I was going to step back and just try to think about it, study it. And I finally got around to that in my scientific research, most of my research is on sexual selection processes and so forth. I only got into the value stuff about the year 2000. And so I’ve had this very, very strong interest in how these people I grew up with got to be that way. Then, when I went off to university, I went into a relatively liberal place. So then I became interested in how these people, how these liberals got their mindset too. I was more like them. And so I go back a long way in my interest in this. And it’s just been really satisfying to understand the cause, to do the science on it and really understand the causal stuff and stuff that happened in my family and so forth. I’m trying to do a popular book for the intelligent reader on all this. But there was one incident where in the old south, middle class and upper class families, white families, would hire a black woman to raise the kids or black women to raise kids. And my family did that. And I was closer to this woman really in many ways than I was my birth mother. And she died when I was 13. My black mama died. And she got sick. And my family wouldn’t let me go see her when she was sick, because she was sick. And they were conservative. And they were worried about me. I mean, they were trying to protect me. But I didn’t understand that at the time. And in my mind, she was my mother. She raised me. She was with me every day. And from the time I was born until she died, which is 13, when I couldn’t go see her. And finally let me go to her house. She lived in a little shack, wind shack, on the other side of the tracks, so to speak. And because it was regional segregation, everything was segregated. And so they let me stand on the porch and talk to her. She was inside in the bed dying. But I could talk to her on the porch. And we talked. And she died five days after that. And they didn’t even, my family wouldn’t even allow, didn’t even tell me where she was buried and so forth. I mean, there was that level of conservatism and worry about disease. And I’d go to her grave or something and catch a disease. But what this knowledge of values has helped me with is things like that. And there are lots of in my upbringing that were devastating because of the conservative values that I was dealing with, terrible things happening. And so I think that’s one thing that really has sparked my interest in values. And then of course, I’m liberal now. How did I get that way? I mean, my high school, it was a high school, Decatur, Alabama, is where I grew up, high school, graduating class about 200. And there were about three liberals in the class. I was one. And one of my close friends, he was a liberal, he’s a civil rights lawyer in South Alabama now. And another one, close friend of mine, she’s little, she works for the Democratic Party in Washington, D.C. But most of the rest of them were pretty conservative. And I wonder how I got out of this. And my hypothesis is that I had an interesting genetic constitution because my part of my family was Native American. And so Native American in North Alabama, Cherokee. And so those folks had the local immunity to the infectious diseases that were endemic to that region, the Native Americans. So I got that genetic complement. And I also got the European genetic complement, which had pretty good immunity to lots of respiratory diseases. And that’s another story we can work on. But so I got this odd genetic complement, Native American plus Northern European, the Thornhills and Northern European. And that that reduced my interaction with infectious disease growing up. So unlike the kids around me, I didn’t have all those ear infections. I didn’t have all those eye infections growing up. And unlike most of my friends. And so I think that’s it. Because I think that’s part of the ontogeny, the developmental background of the Bayes. That is, you’re going through, you’re growing up. And how often is your immune system activated? And how long is your immune system activated when it’s activated? That’s part of the developmental background that we propose for Bayes. If your immune system is activated a lot, then you end up conservative. If it’s not, you end up liberal. So I think all that is part of my interest in this too. If I’d been born somewhere else, maybe I’d have never gotten interested in Bayes, than in the old South, you know? Well, I think that’s a really good place to end. I don’t want to end because there’s like 50 other things I’d like to ask you. But that’s been great talking with you. Well, thank you. And so interesting. Your research is, like I said, it’s too interesting, actually. You suggested some good experiments to think about. Yeah, yeah. Well, they’re, they’re, they’re causal experiments. They’re all actually relatively straightforward. I’m supposed to be retired now. And, but I’m trying to do this, this popular science book. And it also be interesting to see if there’s any relationship between even self-reported prevalence of amount of time ill during childhood and adolescence and trait openness. There is a, there is a scientific study of illness, two studies of the illness during childhood, reported illness during childhood is one of the studies and conserve some, some components of conservatism. I don’t remember if the openness is there, but some, and that works. And then there’s another one where they had, they looked at actually health records of children who then became adults. Yeah, adults. And then you have their health records and they did that and showed that the less health the kid had as a, as a child, the more conservative they were. So that kind of, that kind of stuff is out there. So then, okay, so maybe we could, we could, let me ask you what you think about this. When I first came across your work, I thought, is it possible that the human race could rescue itself from the worst excesses of the kind of conservatism that degenerates into malevolent fascism, essentially by wiping out infectious disease? I think the answer to that is straightforward. Yes. Yeah, absolutely. The, you know, I want to emphasize that the parasite stress theory of values, parasite stress theory of values and sociality is a scientific theory. And hence, it doesn’t have any, doesn’t make any moral judgments about, you know, it doesn’t say conservatism is more moral than liberalism or vice versa, scientific theory. No, no value judgments involved there, because it’s scientific theory. But if one wanted to change the values of the future of people, then they the then you have to know, of course, what the causes of the values are. That’s the way you change things, you know, the, you know, causes of things, and you can change them, then you, if you wanted to make the world more liberal, you would reduce infectious disease. Well, you could say that’s imagine you wanted, you wanted to make the world a place where the cost for the free exchange of ideas and people was dramatically reduced so that the countervailing tendency to that was unnecessary. Yeah. And the catastrophes that might go along with an excess of that countervailing proclivity, the most effective way forward would be to eradicate infectious disease. And so and then you’d have the benefit of eradicating the disease, which would be non-trivial, plus you’d have the political benefit, it will be healthier, lower mobility and healthier throughout their lives. And also, they’d be open and, you know, sort of reaching the goal of the true enlightenment, which was all about, you know, freedom of thought and individuality, um, science, knowledge, all that stuff. Right. All entirely laudable goals, except when the cost becomes too high. Yeah. When diseases are out there. Well, so I’ve been talking to people like Bjorn Lomborg and Matt Ridley and, and, and, and, you know, there, there are people who have a positive enlightenment view of the future and are having a hard time in some sense, along with the rest of us generating something like, what would you say, a noble vision for the future that moderates could get behind and be motivated by. And it certainly seems in light of this discussion that, and of what’s happened with COVID-19, et cetera, and the fact that infectious diseases are still a primary killer and not only that, crippler of people all around the world and that they contribute radically to all sorts of political instability, that one thing we could all agree on would be that less infectious diseases would be better. Yeah, absolutely. Absolutely. And, um, you know, I have a pretty positive view of the future. Like you’ve, you’ve, um, I noticed on your website that you interviewed Steve Pinker. Yep. But he’s in the same group in some sense as these other people that I just mentioned, you know, they’re, they’re optimistic enlightenment figures. I can be optimistic. And, and, and he sees, he has data on how much things have improved over the last several centuries. And that’s because of lower infectious disease. I mean, he doesn’t have a theory. His was his, his ideas, just stops it. He’ll think people got enlightened, but how come they got enlightened? You know, why did the enlightenment occur? And, um, why did we allow it to occur? Yeah, exactly. Absolutely. Better and better. Why did, why did mortality and, you know, uh, homicides and wars and all that reduce in frequency and, uh, all the evidence we put together says it has to do with lower infectious disease through time. That’s what happened. That’s what’s behind that trend. That’s why that’s, that’s, that’s the key to our better angels. Thank you very much. Sure. I appreciate it. It was great discussion. I really, I learned a lot and your work is, it’s remarkable. Yeah. Well, uh, I may call on, may well call on you again. Thank you.