[The Evolutionary Science of Infidelity: Insights from Mackin Murphy]-[#825 - Macken Murphy - The New Science Of Why Men & Women Cheat]

Modern Wisdom · B2 · 2024-08-15

📋 Summary

Unveiling the Evolutionary Drivers of Infidelity

In a deep dive into the evolutionary psychology of human infidelity, researcher and biologist Mackin Murphy challenges long-standing assumptions about why humans cheat. Moving beyond the simplistic notion of "novelty seeking," Murphy’s recent research provides empirical weight to the "dual mating hypothesis," offering a nuanced perspective on how humans navigate romantic relationships and extra-pair mating.

The Dual Mating vs. Mate Switching Debate

For nearly two decades, the dominant evolutionary theory regarding female infidelity was the dual mating hypothesis. This theory suggested that women might engage in extra-pair affairs to pair the "good genes" of an affair partner with the parental investment of a primary partner. However, this hypothesis faced a "reckoning" in the 2010s when experimental support—specifically regarding "ovulatory shifts"—failed to replicate consistently.

In response, some scholars proposed the mate switching hypothesis, arguing that affairs are primarily a strategy to "trade up" to a better overall mate. Murphy’s study sought to settle this debate by testing these predictions directly against one another.

Empirical Findings: The Crossover Effect

Murphy and his team recruited a sample of 254 individuals who had experienced infidelity. By having participants rate both their primary and affair partners on specific traits, they uncovered a significant "crossover interaction":

Affair Partners: Were rated approximately two points higher in physical attractiveness.
Primary Partners: Were rated approximately three points higher in parental attractiveness.

This result strongly supports the dual mating hypothesis, indicating that humans (both men and women) seem to prioritize "conceptive benefits" (genetics/attractiveness) in affair partners, while maintaining "parental benefits" (stability/investment) in primary partners. Notably, the mate switching hypothesis received little support, as there were no statistically significant differences in overall mate value or personality between the two groups.

Deconstructing Motives: Qualitative Insights

While relationship dissatisfaction was the number one cited reason for cheating across genders, the study highlighted significant differences in how men and women perceive their motivations:

The Gender Gap in Satisfaction: Women were over twice as likely to cite "relationship dissatisfaction" as a motive compared to men. Murphy argues this is likely an adaptation; because infidelity carries higher social and dissolution risks for women, they are more sensitive to internal cues regarding relationship quality.
The Physical Attraction Disconnect: Despite only 5% of women explicitly mentioning their affair partner's attractiveness as a motive in qualitative interviews, quantitative data showed they were 77% more likely to prefer the affair partner's physical appearance. This underscores that individuals often lack full insight into their subconscious evolutionary drivers.

The Role of "Skill Issues" and Partner Selection

Murphy also explored why some individuals are repeatedly victimized by infidelity. He suggests that "repeat victims" may be selecting partners who possess traits that covary with infidelity, such as high narcissism or a history of promiscuity. He notes that while "once a cheater, always a cheater" is a rough heuristic, longitudinal studies confirm that previous infidelity is a strong predictor of future behavior.

Conclusion: Humans as Strategic Agents

Murphy concludes that the evidence does not suggest humans are inherently non-monogamous, but rather that we are "socially monogamous mammals" who exhibit extra-pair mating strategies. The controversy surrounding these findings often stems from political discomfort, but Murphy maintains that these behaviors are not "conscious" machinations. Instead, they are the result of deep-seated psychological adaptations. By viewing both men and women as "active sexual strategists," we gain a more accurate, albeit complex, understanding of human nature that moves past the "midwit takes" often found in public discourse.

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allure of novelty

one and done

game changer

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📖 Transcript

What's happening people?

Welcome back to the show.

My guest today is Mackin Murphy.

He's an evolutionary biologist at the University of Melbourne, a writer, and a podcaster.

Why do people cheat? Is it just the allure of novelty dissatisfaction in their current relationship, fear of being left, retaliation for their partner cheating?

Mackin's brand new study gives so many fascinating answers to all of these questions.

It's got a cutting edge ceramic blade to reduce grooming accidents and 90 minute battery so that you can take a longer shave, waterproof technology which allows you to groom in the shower and an LED light which illuminates grooming areas for a closer and more precise trim or if you just wanted to do it in the dark.

And you know during the late 90s and the early 2000s and to an extent the 2010s as well I would say that most evolutionary psychologists would have said that the primary driver of women's infidelity from an evolutionary perspective is the powerful benefit of being able to obtain better genes right better in a fitness sense not obviously not in a moral sense.

And we might end up saying you know the phrase good genes quite a bit on this show and every time it's always in it's always good in a fitness sense but in any case the mainstream idea was that infidelity is a conditional strategy that women sometimes employ in order to obtain better genes for their offspring right so to pair the genetic benefits of one male with the parental

So everyone when we're looking for mates there are two things that they can give our offspring they can give our offspring genes obviously or they can give our offspring investment and normally women get genes and investment from the same person but the idea was is that women's infidelity allows them to get genes from one person and parenting from another.

So the idea was and it was a very clever hypothesis originally before by Steve Gangostead and Randy Thornel which is that if it's true that women's infidelity functions to pair quote unquote good genes with good parenting well women can only get pregnant during a brief window in their monthly cycle and so it would only really make sense for them to have a fairs during that time

right because the risks of infidelity are evenly distributed right infidelity is a very risky behavior you could lose your relationship you could be subject to retaliatory violence or social penalties and and so it would make sense for women to engage in the you know genetic strategy during their pariolvulatory phase and the parental investment strategy during the rest

of their cycle and so that was their hypothesis and the first tests which were with and this isn't their fault but small samples and relatively primitive methods those looked quite positive then as methods got better the these effects either shrank or disappeared depending on who you ask right it seemed to be analyzing the original data no not reanalyzing the original

data collecting new data with better methods right although there has been some questions about the original data as well so so one example of this is that some of the early studies would use would determine when a woman was in her cycle based on self-report counting so count since her last period essentially and that's just not that that's not a completely inaccurate

method but it's not exactly high reliability and then later methods that use more you know direct tests and just better bigger samples and also you know pre-registered in some cases just better methods overall they they made they made this ovulatory shifts sub hypothesis of the dual mating hypothesis right they made this look less good and so some scientists

led by David Boss but it was it was quite a large number said well hang on maybe it's not just that ovulatory shifts aren't happening maybe dual mating isn't happening right so dual mating is something that we see in some other animals to an extent like we see for example that red-winged blackbirds the females will engage in infidelity with males who have more robust

bodies right fly catchers another one where they they've got nicer plumage the the the affair partners compared to the primary partner so it's not something that's without precedent in the animal kingdom but other animals like cockatiels for example when they have affairs their affairs are geared towards something called mate switching so the affair is a way

of cultivating and obtaining a new and from a reproductive standpoint probably overall better mate so they put forward this idea that you know hey maybe humans are more like cockatiels than fly catchers maybe the underlying theory so we've got dual mating this you know quote unquote good genes good parenting combo deal maybe it's not a combo deal maybe it's a best-whole

package type situation maybe that's what female infidelity is geared towards obtaining so that was the the history of the debate and they put this alternative idea forward and it wasn't based on you know this new idea it was a hypothesis that was put forward it is a hypothesis that is put forward based largely on what we would what we would call circumstantial evidence

right so it's drawing together a variety of facts from past studies and forming inferences about them right about about these about what's happening from that so it's not that there was some experiment that showed mate switching was very common in humans it wasn't that we collected some you know awesome data set and it showed mate switching that's not what happened

it was just an alternative hypothesis and then after that Brooke Shelza tried to test the mate switching hypothesis in her population at least the trading up function of it she tried to test it in her study population the Himbabwe of that's a group of aggro pastoralists in Namibia and she didn't find evidence for the mate switching hypothesis she found slight evidence

for dual mating and then she found evidence that a lot of women's infidelity in this area was geared towards obtaining additional resources from additional mates so it has an additional function and this is a theme that we'll probably talk about more so there was a little bit of evidence for dual mating women seemed to have a hot put a higher premium on physical attractiveness

and a fair partners but the mate switching hypothesis camp at least in what I read they seem to kind of I won't say brush it away but they seem to interpret that as saying as just applying to that population right so it's like okay the mate switching hypothesis didn't work but it's in this pretty unique population and I think that's fair enough because the Himbabwe

Well the mate switching hypothesis has quite obvious and intuitive predictions if you're looking at the trading up function some scholars they would classify backup mating and break up mating as part of mate switching but we're looking at trading up if women are cheating to obtain a better mate then they should perceive their a fair partners as better very simple

prediction probably better looking better as specifically as a potential co-parent since that's who they want to switch to overall mate value should be higher maybe a more attractive personality right that I guess that could go both ways and so what we did was we set up an experiment where we had them where where we collected women who and men so we collected a large

sample of women and men who had actually had a fairs because this was a problem with the previous literature even especially the literature you know in the mate switching dual mating debate not Brook Shels' work was that most of it was done on people who hadn't had a fairs why do you find people that have had a fairs I wish I could say something fun like like Ashley Madison or something

that we're recruiting on Ashley Madison but that's not what we did what we actually did was we put up a large survey that has been seated on your partner come and do a survey yeah well yeah it was basically free questions it was like well it was demographic questions and then it was have you ever been in a relationship that was you know sexually exclusive in any of those

relationships have you slept with somebody else at any point and would you like to do our study right and we sent that out to I think it was 1500 people and quite a lot of people said yeah I actually have had an affair at some point but it was a relatively a small subgroup let's say that actually wanted to go through all the way and do further research with us so and that final

sample was 254 people for those who were interested so let let's circle back to the predictions here so if the mate switching hypothesis is true and we're looking at people who have actually had a fairs well then women should rate their affair partners as more attractive in some way but certainly more attractive overall and more attractive as a potential co-parent

those would be the things that you'd really expect to see if the mate switching hypothesis were true the dual mating hypothesis has different predictions so the dual mating hypothesis would predict that there'd be kind of this crossover effect where the affair partner is rated as better physically right like physically more attractive but parental they should be

less attractive right so if if if women's affairs function evolutionarily to pair good genes with good parenting well then the primary partner should have better parenting right wouldn't the alternative wouldn't really make much sense I'm not sure I don't quite understand that why would it be the case why would dual mating not predict better parenting as well

because dual mating is pairing the good genes of the affair partner with the parenting of the primary partner so it's essentially a process where women will have an affair right or female animals other species will have an affair right and try to pair the genes of one male and this and this is again none of this is meant to be conscious we're we're looking at the subconscious

evolutionary drivers of our behavior the structured psychology underlying it so it's so I guess to summarize mate switching would predict that a fairs function to obtain a better mate overall whereas dual mating would propose that female infidelity functions to capture quote unquote better genes and pair it with better parenting better investment and so these

these are these are distinct distinct hypotheses and you know I'll flag post here that we're signpost here that none of this is meant to be conscious per se right it doesn't this isn't implying that anyone's deliberately trying to you know in the same way that when we enjoy sex right we're not thinking consciously oh this is great because I'm gonna get to have kids

and in fact we might be thinking the opposite right it's more what psychological biases undergird our infidelity and you know we have very good reasons to suspect that infidelity did evolve it appears cross culturally that's the first sign it appears you know this is something that your your friend Steven Stewart Williams likes to share which is that if a behavior appears

even where it is socially discouraged it's probably not socially constructed right and we see that infidelity is very harshly punished and people still do it and then also humans are socially are mostly socially monogamous mammals and if you look at other socially monogamous mammals and other socially monogamous primates extra pair paternity has some degree

of presence extra pair of compilation is documented with quite a high frequency so we have very good reasons to suspect that this evolved and so given the dueling predictions right that the dual mating hypothesis proposes that it's better physical attract oh and here I actually not to just over caveat but why would physical attractiveness be a sign of good genetics

good genetics quote unquote I would say listen to our last episode I mean Chris's last episode covers that in very high detail but the short TLDR version would be that one a lot of the things that we find conventionally attractive are just cues to health so you know the things that we think are good looking the reason that they're conventional is because they signal

heritable benefits such as good health and then another idea is just that physical attractiveness itself offers benefits and is itself heritable good looking people tend to have good looking children and so it would make sense that given the tremendous benefits that come with being good looking you would want a partner with quote unquote good looking genes

anyway so different predictions may twitching predicts that the affair partner will be better overall and better as a co-parent dual mating predicts that the affair partner will be better looking but worse parenting right or yeah worse parenting really it's the primary partner should have better parenting as the is the correct way to think about it and so what we

did was we took everyone in our sample and we had them rate their affair partner and their primary partner separately on valid and reliable scales and our study was pre-registered it's a very diverse sample and compared for differences so we had them rate their affair partner and their primary partner's physical attractiveness parental attractiveness mate

value their overall desirability and also their personal attractiveness although that to be fair that could have gone that could have gone both ways it might it would have been interesting but not necessarily consistent or inconsistent with either hypothesis and what did we find well we found that affair partners were about two points more physically attractive

on our scale on average and primary partners were about three points more parental attractive so we had this you know crossover interaction between rating type and attractiveness which was really the best case scenario for the dual mating hypothesis it's also very unlikely just for for those at home it's very unlikely that you would find this sort of structure

by accident because usually better looking people because the halo effect and just positive perceptions in general they're going to get better ratings on everything and so it's very strange for one group to be better looking but worse parenting this is a very unlikely thing to see if there's no structured psychological adaptation involved so the dual mating

hypothesis was I would say strongly supported best case scenario pre-registered study on actual women who have had affairs signaling this and the mate switching hypothesis there was no difference in mate value overall mate value overall desirability even between affair partners and primary partners no statistically significant difference and no statistically

significant difference in personality either so our study ended up being the best case scenario for dual mating and the worst case scenario for mate switching so I guess we started this conversation with you know why has this why would this cause controversy well it kind of seems like everyone has been a little too hasty in dismissing dual mating based on the fact

that the ovulatory shift studies don't replicate but the truth is is that ovulatory shifts are just a sub hypothesis of dual mating and human sexuality is actually unusually stable across the cycle and so maybe it was a I mean I still think it's cool hypothesis and maybe more complex methods will prove that there are there is something to you know human estrus but the truth

is that dual mating doesn't need this hypothesis it's just a sub hypothesis and the more important thing is that is that we do seem to have different priorities in our fair partners versus our primary partners and one thing that I'll flag maybe we can talk about this later because it's the more confusing and maybe the most interesting result from our study is that men

showed the same pattern so men also contrary to conventional wisdom men also tended to cheat up in terms of physical attractiveness and cheat down in terms of parental attractiveness a lot of people responded to our study basically saying huh I would have thought that men cheat down across the board basically because it's easier right kind of the the man is only

as faithful as his options and most men have more options that are less attractive than themselves that that didn't really seem to be supported and then in our qualitative data we did we also didn't find any differences in novelty based so I would say that the overall picture the dual mating hypothesis traditionally has focused on women but I would say that it's

really a human strategy in the sense that humans in general it's different what benefits are sought but humans in general see seem to prioritize conceptive benefits in a fair partners and parental benefits in primary partners this is just one study of course and you know I did design the study to be persuasive to myself so I am persuaded by the result right but there

are other results that converge with that converge with us in terms of at least the physical attraction side of thing that a fair partner's time to be more attractive and primary partners less so I've spoken for quite some time so I'll not at all what what is the evolutionary function of men following that same pattern when it comes to infidelity it's a little confusing

right so I know that you've obviously had a pretty intense crash course in Eveside talking to all the the world leaders in the field let's say and so you would be aware of the fact that if you ask an evolutionary psychologist why do men cheat they're gonna say oh easy more mates means more offspring for male mammals they're gonna talk about you know genges con and they're

gonna talk about you know how the ceiling is basically unlimited for a man reproductively if he just has enough mates whereas for women the ceiling you know in theory and you know if you believe the accounts of Valentina Vaslev this is this kind of a funny anecdote to illustrate the conventional abseye view Valentina Vaslev was a Russian peasant and I believe she

had 60 something children all with her husband right and then her own husband so she's the she would be if it's true she would be the world record setting mother as a woman right the the most prolific the most prolific women woman in childbirth and then her own husband if you believe the gossip her own husband outpaced her by having a fierce and he had like 80 something

so the idea being that a woman can in theory and potentially in practice maximize her reproductive output with just one male whereas a male can only maximize the reproductive output by seeking additional mates so that's the conventional wisdom in abseye our study it's not inconsistent with that right like we didn't design our study to test the hypothesis but then

we didn't find support for this hypothesis where we expected to find it so one prediction that I think would be pretty natural from that idea that men's infidelity is purely quantity driven right so the women's infidelity hypothesis mates switching dual mating both of those are both of those are quality hypotheses and then the main male hypothesis is a quality

hypothesis right and so you'd expect I think that you'd expect to find that men cheat down right to maximize their numbers so to say and then you'd also expect when you ask men why they cheated you'd expect them to report variety driven motives at a higher rate than women it could have been because of our study design we also asked participants just straight up why

did you cheat I believe we've got certainly the evo literature the maybe I won't say this but certainly one of the largest data sets on just people saying why they cheated from our qualitative data and men and women both reported you know sexual boredom a desire for novelty there were no statistically significant differences in that area maybe a better design would find

that but there was no sex differences in proximate reasons for why people cheat they're well there were sex differences in proximate reasons but not the not in the novelty area right and not in the boredom area and not in the combined measures of both of those not in the variety area generally but I think that that's just because I mean maybe I'm being too generous

but I think that we have to be really skeptical I think our quantitative data is really good really reliable our qualitative data has unavoidable shortcomings that come from just you know interviewing people right if you just ask someone why they cheated people don't have perfect insight into their own motivations and then they also aren't perfectly honest

right humans are storytellers we like telling stories where were the hero and so we're gonna you know downplay motivations that are unseemly or subconscious and we're gonna play up motivations that are flattering like I'll give you an example of this that's that's pretty stark so we asked women what motivated you to have an affair and about 5% of them said oh is because my

affair partner was really hot right just he was super attractive that's part of the reason why I had an affair so 95% of women didn't even mention it but then in our quantitative data women were 77% more likely to prefer their affair partners physical attractiveness then to prefer their primary partners physical attractiveness what a coincidence if that's not a motivating

factor right so we have to be I am happy with our qualitative data but we have to be careful with it I think the only thing that it really shows is strategic diversity how do you know that that's not just novelty seeking it doesn't need to be better it just needs to be different yeah so there there there was there was a bit of that I would say that about one in 10 people in our

our again our our quantitative data doesn't really get a novelty but it does suggest that it's not just novelty because from a physical attractiveness perspective on average it was better right but that's the the my point being that physical attractiveness is inherently a subjective you're asking you participant what do you think about the rating of A and B which I'm

sure you can see is being open to just straight novelty itself as you've said we are not a clear pool of water that we can see down into the depths of if you were to get people to say okay show me a photo of both your affair partner and your main partner then let's get other people to rate whether they think which one is more attractive compare that to their answers yeah that would be

fascinating that would be a very good test how much of a role but can you send me a photo of the person that you're in relationship with and the person that you cheated on them with please that would be great thank you yeah the the ethical nightmares that you've just designed oh yeah and by the way I'm going to show these I'm going to show these to loads of people yeah yeah

yeah yeah yeah so that would be a bit ethically fraught but a good genuinely good study design that would that would be a test of our hypothesis I guess one and I think that that's a legitimate limitation it could be that novelty itself is causing more physical attraction that seems plausible to me but if it were just positive illusions associated with novelty I think

you'd expect higher ratings overall it's weird that this is only happening with physical attractiveness so we all know that you know in the early stages of a relationship we tend to have these you know very biased views very positive the guy is everything yes they're wonderful they're perfect and so if that's what's causing the physical attractiveness gap very

peculiar that didn't happen for mate value very peculiar that it didn't happen for personality and extremely peculiar that actually reversed for parental attractiveness so it's a legitimate critique and I would be interested in the I would be very interested in the results of that study if anyone can get ethics approval for it dude but I'm the king I'm the absolute

king of coming up with studies that you can't do you know I'm like a I'm like one of those rock stars that never actually learn to play classically and is able to like I'll do it left handed and upside down it'll look awesome but sound terrible that's my that's my sort of contribution to the world of of Eve's icon you know that ecology that and giving us giving us cool cool

terms cool you know I'm good at me mean me mean me mean coming up with studies you can't do I'm digging to what else you learned from a qualitative perspective what was what was interesting what did men say what did women say and sort of how does that tie in with your new reinforced perspective of infertility well sure I mean so the top motive the first thing to notice

would be that the top motivation for men and for women was relationship to satisfaction in their stated motivations so the way we did this was we read I was it took a very long time we read all of the responses and our data is public by the way other people can also look at you know if you want to read hundreds of reasons why people had affairs and get a gist you can just access

our data it's fine and we read through all of these we coded them for themes so that's when you basically write down like oh this one mentioned that the affair partner was hot that kind of thing so we coded them for themes and then we went through and we found the themes that were repeating themselves and then myself an elab assistant went through and we separately recoded

these items to see you know where the which themes were occurring at what rate and then we ran statistical analyses to test for sex differences so that's our methodology relationship to satisfaction was the number one stated motivation for infertility in both men and women however it was a big sex difference as well so only 30% ish of men mentions relationship

to satisfaction in their answers so most men even though this was the most common response most men didn't bring it up whereas 65% about about 65% of women mentioned relationship to satisfaction so women were twice as likely to bring this up essentially over twice as likely even though it was number one for men even though it was number one for men press does that mean that men

had a sort of flatter distribution of reasons in that case not necessarily that that inference would be correct if we coded them one to one but the way that we coded it was that one one affair could have multiple motivations so for example a participant might say oh I was in a long distance relationship and things weren't going well you know she really wasn't treating

me right and my affair partner was just gorgeous right that would be a pretty that would be a pretty reasonable answer that would be the sort of thing that we'd see and then that would get coded as attractive affair partner long distance relationship and relationship to satisfaction so it doesn't necessarily mean flatter distribution of reasons because we can recode

variables in this way but great question so historically right the whole women are more likely to have relationship to satisfaction when they commit infidelity that's a that's an expected sex difference it's something that pops up in let's sure quite a bit since the 80s why why is it expected well it's funny because the original logic was that was that it was evidence

for the mate switching hypothesis because it's like oh if women are usually dissatisfied when they have affairs that means that they want their relationship to end right two reasons I'm skeptical this one women are women often have higher relationship to satisfaction anyway right a given given certain circumstances they might be more more sensitive to cues

that the relationship is not going well there also might just be a difference where they're more likely to express dissatisfaction even if dissatisfaction levels are in actuality even between the sexes that's number one number two and this is more important and more deeply theoretical which is that infidelity as we discussed earlier is a very risky activity

and it is especially risky for women so based on Martin Dalley's research I believe you might have spoken to no I'm lining up I would have called him daily so I'm glad that you fact check me on it might be daily it might be daily I've only read his name I mean it's only it's only your industry mate so yeah I'm speaking I'm speaking to Martin through a combination of Rob Kerzban and Steve

okay I think I think he'll be great yeah no he surely will be he's written just some of some of my favorite stuff has been written by him but some of his early research basically found that women's infidelity is more likely to result in relationship dissolution than men's infidelity and so this is a funny way of thinking about this but in Evesite it's pretty common to

think of relationship satisfaction as an internal regulatory variable that partially tracks the value of your relationship and so if your relationship satisfaction if you risk your relationship every time you have an affair and your relationship satisfaction is low well then you're literally risking less than someone who is a relationship exactly exactly

and so if infidelity is more likely to result in relationship dissolution for women than men then the risk is at a baseline higher and so you should expect that women should be more likely right to be attuned to whether they have the infidelity discount that comes with relationship dissatisfaction and so this has been interpreted as evidence for the mate switching

hypothesis and I think it's reasonable to say that someone who's relationally dissatisfied is more likely to be mate switching with their affair and some some people do mate switch you know several women in our sample but only several said that they were mate switching but I think it's reasonable to assume that they're more likely to be mate switching than someone

who's really relationally happy but I don't think it's reasonable to do the reverse inference which is that because they're relationally unhappy they want to mate switch there are plenty of people who are relationally dissatisfied having an affair but also want their relationship to keep going and that's also quite intuitive to me this idea that you know sometimes

relationships are unhappy but you you want to stick things out what do you make of the difficulty that women supposedly have in separating their emotions from having sex with a guy that women will fall more when they are physically intimate with a man because there is a higher hurdle for this man to get over that it is her being more risky would it not be the case for mate

switching that women would be more likely to fall for that partner still even if it's not sorry for dual mating even if it's not for the purpose of mate switching while they're dual mating would it not be more likely that they were going to fall for that partner in any case is a sort of a natural byproduct of the the feminine desire to be emotionally intimate with someone

that's very clever I haven't considered that and I have to think about it more because I mean you're familiar with the mate switching hypothesis but what Chris is referring to here I believe is that there's a one of the flagship pieces of evidence for the mate switching hypothesis is that women are more likely to fall in love with their affair partners than men are and what you're

saying is that women are more likely to feel emotionally entangled with sexual partners in general and so that also isn't necessarily particularly good evidence one thing that I will note is that we didn't find that love for a fair partner is was coming up much at all right we're talking like one two percent like they know just it was I can't remember it was sub five

percent very few people in our sample men or women said that they were motivated by love for their fair partner that just didn't come out very much and so I I'm a bit skeptical I mean maybe it is the case that women are more likely to be in love with their affair partner right but at least in their stated motivations it doesn't seem to be a big factor in why they had the affair

to begin with and so it might that might be even though that's my favorite evidence for the mate switching hypothesis as you say it might not have as much theoretical move to it as it seems to at first first glance and then also the there's an inference involved there where it's like if they love them that must be their motivation and it's possible to be in love with your

fair partner and have that be pretty low on the list of why you had an affair yeah yeah I remember Andrew Thomas talking about what women say that they want in terms of traits when choosing for sperm donors so everybody's egenicist right everyone is everyone is whether you like it or not and some people are more quantitatively and obviously egenicists if they choose

sperm donors or if they choose a like to if they go through IVF with a donor for either side I suppose and one of the things that I thought was really interesting that Andrew brought up is women who choose sperm donors it is the only time where the traits that you want in your future child are divorced from the traits of the man that is able to get you into bed to be able to

create that future child so you have this sort of weird territorial cutoff which is what do I what do I want my future kid to be like without having to jump through the hoop of what is the sort of thing that I find attractive that gets me into bed so it's kind of a much more sterile controlled environment when it comes to doing that and given that with regards to dual mating

it surprises me that things like a personality didn't include in that given that although you want sexy sun hypothesis presumably you want likable sun hypothesis it's interesting in our pre-registration we didn't make specific I guess I guess one thing that I'll note on the on the eugenics point is that I've heard a lot of people say that say the same thing of kind

of like it's it's sexual selection is eugenics I personally do see a difference between individual level what do what traits do I want my child to have right in the case of you know embryos selection in the case of IVF and sperm donation and then what traits do I want to be high frequency in society out large that's a good yeah I'm yeah that's you're perfectly acceptable

to do that there's a difference between you know two bees concern about that gene erosion thing that that sort of scaling up even though I think it's still largely ethical that's more of a scaling up that being said the one conversation that I've ever had about embryos selection I got called an actual Nazi for having so but it's it's it's it's okay I'm over it I mean I'm

not I'm not someone who's super into science philosophy I'm sure that someone's listening and just thinking that I sound like a bit of an idiot but I will say that I don't see a huge difference between I mean maybe I'm just thinking about this wrong but I don't see a huge difference between selecting an embryo and selecting a mate at the individual level where I would find

it where I would start defining it as eugenics and start defining it as you know ethically a porant to myself would be when people are telling other people what they should do or when the government is getting involved and trying to adjust yeah trying to adjust any top down trying to adjust the frequencies of genes in the population I would see that I would see that is very

very bad but at the individual level I don't really understand I mean I also don't really understand embryo selection to be honest it's not my area I'm I'm you know I'm an expert in very few topics so we'll stick to those okay it is interesting of course anything else from the qualitative insights that you learn yeah yeah I think it would be cool to just go over the top

three motivations for oh actually can I just ask though what what was Andrew Thomas what was his actual conclusion on like what traits did they want from sperm notice that's very relevant to the dual mating I can't remember let me see if I can pull it up and through now the advantage of having 3200 notes okay I did you conducted an experiment where you ask chat gpt for mate

preferences no I can't I don't actually I don't actually have it on there I certainly know that but things like kindness were much more prioritized it seemed to me to be softer skills what if you want to call it that sort of the soft skills of being a being a person so I think in their kindness humor intelligence yeah it was it was more prosocial stuff I think which maybe

you might you would probably be able to predict pretty easily that you can look away from someone's dark triad adjacent personality traits because they're hot or cool or funny or something interesting it's funny because embryo it's because you know sperm donation embryo selection all of these it's all it's hard to know if it's stated or revealed preferences

it's hard to know where to put it there was a really cool study from Paul Eastwick and his colleagues just awesome where they looked at this is very recent it I think it's still in press so it's not even fully published yet but it is fully pure viewed it's going to be published as is and they looked at what people say they want in a partner and then they looked at how what they

say they want actually predict romantic evaluations in practice so that stated preferences on one end and then kind of a version of revealed preferences on the other end and there were some kind of funny examples the number one stated preference trait was loyalty that's what people said it's like what do you want in a partner number one thing loyalty and the number

one revealed preference was being good and bad a good lover so there's that I took that table from your from your Twitter so yeah they said the first rank was loyalty but that to be fair that ranked is number two it still ranked as number two yeah that's the other thing is that it only got suppressed a little the main thing that was shocking was the how much so well it was a good

a good lover jumps from rank 12 to rank one I know people don't like it's good it goes back to what we were saying about the people want to tell stories in which they're the hero it doesn't sound great if you're asked by a psychologist you know what do you want to mate and the first thing you say is good and bad you sound quite unhinged but in practice that might actually

be more predictive of your romantic evaluations than anything else and it certainly seems to be in the large sample and then they also found that in general I think that the general gist of that table is that traits physical traits are much more important than people say and they're especially more important than women say so for man and women sexy jumping from number

19 to number six yes yeah that's a huge jump smells good that's another just physical trait whether you smell good or not what was that I know it jumps to like number four but it was smells good oh number 15 to number four attractive number 16 to number eight yeah so if you want to contrast what people say they want and what people actually want one of the main things that's

going to come up over and over again is that people under state and this doesn't necessarily mean they're lying it could just be that we don't have perfect insight into what makes us happy but we understate how important physical attack pill the black pill was right all along you just need to smell nice yeah yes the new black pill just dropped smell smell smell smell

max smell max smell so smell maxing right now yeah um okay qualitative the rest of the qualitative yeah the rest of the qualitative stuff so so is that those a diversion but a happy one and and one that's actually relevant because we in a way we found the same result again five percent of women mentioned that their fair partner was physically attractive and then they

were 77 percent more likely to prefer their fair partner physically what a coincidence but top motivations for women relationship dissatisfaction number one and a high number one again most women mentioned that second place and second place by quite a bit only only 20 percent that's still a high 22 percent um mentioned that their primary partner was uninvested

and this also illustrates an important point which is that not all women's affairs are explained by dual mating it seems that there might be a psychological bias towards the dual mating strategy but many women had affairs with affair partners who they perceived as less attractive right 77 percent more likely is not you know that's not an infinite gap and then um

I fear there one of the reasons that many women cheated one and five women cheated precisely because they thought that their primary partner wasn't invested enough so if it's pairing good genes and good investment that doesn't make that doesn't make a lot of sense um with for those women and then the third most popular motivation for women was revenge so 15.5 percent

of women said that they were cheating to get revenge and men didn't they say what on um well in this case the 15.5 percent figure is revenge for their partners affair specifically so I remember I spoke to a guy who was kind of an unofficial marriage counselor in his neighborhood and I asked him you know why do women cheat in your experience like what what you see and he

very flatly said he said women cheat when men cheat now that doesn't seem to be a hundred percent true but there's certainly some truth to it in our data in the sense that women were much more likely to cheat for revenge and you could interpret that as a genuine strategic difference but since men cheat more than women women have more opportunity to cheat for revenge

or the very least they have more opportunity at the very least they have more opportunity to cite revenge as one of the reasons why they cheated whether it was going to happen or not yes what uh what what is the state of who cheats more men or women oh that that's a pretty open and shut case men cheat more men say they cheat more when you ask them uh men say they get cheated

on less when you ask them so women report getting cheated on more and then women who are the third person right so some people might say oh well maybe women are just understanding things when you ask you know who's more successful as a mate poacher uh women who mate poach tend to have a higher hit rate so there are three people involved in any given affair there's the primary

partner there's the person who's cheating and then there's the affair partner and you can do studies on anyone of those three groups and you generally find the same result which is that the man is generally more likely to have an affair in some studies it's not a big gap in some cultural context it's a huge gap but that would that would be the overall state of the science

there and so the revenge difference it may just be downstream of uh the sex difference in committing infidelity they have more opportunity to have an affair what do you what do you learn from a woman's concern about investment from that partner to good question so this is pretty consistent with it's not consistent with the dual mating strategy but it's consistent

and it's actually a really good thing to illustrate that women cheat for many reasons they cheat maybe for traditional variety based motivations such as genetic heterogeneity or you know fertility backup so some percent of couples are infertile and so if you're mating with multiple males you're really lowering the probability that that's going to result in the end

of your lineage um there there there are many motivations for affairs revenge um so on it so on it having it being being an uninvested partner low investment i would say that it signals i would say that it signals kind of the traditional evsike difference which is that women's investment in offspring is largely obligate physically obligate in the sense that women

have to go through pregnancy and lactation this is part of why women seem to be more careful about who they mate with more choosy uh a lot of men complain about you know women having high standards for their mates but really what do you expect right like if you could get pregnant surely you'd be pretty careful as well about who you mate with and so women's investment

is partially obligate whereas men's investment is not morally but pragmatically entirely optional men have the option to seduce and abandon mates and so you'd expect given that that women would be very sensitive to cues that a man might seduce and abandon her and really try to avoid that as much as possible and so if they're in a relationship and they think oh my

my partner's not investing in me he's not invested well that's a huge signal that he's a low mate value mate essentially it's like oh i this isn't going to work and maybe that maybe that's evidence for mate switching but maybe it's also evidence for break up or backup or just lowering the cost of infidelity again the discount infidelity idea i was going to say you know

this doesn't mean that no woman ever leaves her partner to get into a relationship yeah with the cheating partner yeah reliably that does happen and also i'm going to guess that if you looked at the cohorts of women and you were to find the one that said i was worried about investment from my relationship partner that would probably result in more likely of a pivot

to the new infidelity partner as a new relationship i'm going to guess that that would probably be predictive of that because like what am i sticking about for if i'm going to have genes and investment and i don't have investment then i might as well try and get genes and investment to guess exactly so the so the dual mating it doesn't explain all of women's infidelity

certainly and we did see some mate switching in our samples several women in our sample were mate switching i'm wondering whether the uh era that we were in in sort of 2017 when we look at the mate switching hypothesis the dual mating hypothesis feels a bit icky to me like when you think about it when you think about and maybe this is just me as a man but thinking about some

guy male parental uncertainty raising another man's children whether this is or is not during a period of oblioletry shift where you're fertile as a woman it makes me go like you know it's a little bit more a macchi valiant it feels like in that way whereas mate switching seems to just be okay your monkey branching from one relationship to the other people have backup

mates people have you know their friends at females friends that are men often tend to have the attributes of the sorts of men that they would get into a relationship with which kind of has the sort of weird quasi orbiter backup mate things floating around a little bit i wonder whether in a post me too world that was just a bit more uh who's a little bit easier to digest

uh to have something that was a bit less like oh i know i mean i don't really in terms of assessing theories i don't really care about how icky they are or how yeah it just doesn't affect my assessment of the fact i just want to know what's true whether or not it's kind of gross and i would say that the evidence points to this idea that this is a part of human evolution i mean in modern

populations quote unquote cuckoldry is quite uncommon uh you know one percent two percent three percent that would be those would be the sorts of estimates that you'd get from people who really understand the subject that would be of them one to one to three percent are men raising a child that they are unaware is not their genetic offspring yeah well yeah yeah yeah

exactly uh one one two three percent kids of kids are you know you are not the father type situation but the male sensitivity to uh parental uncertainty though has to exist for a reason yeah exactly if it never happened exactly we wouldn't how could we have how could we have such concern with paternity certainty if there was no paternity uncertainty to be concerned

about that's number one number two the modern percentages are based on their base in a cultural context where infidelity has been highly suppressed socially and they're based in a technological context where we can choose through contraceptives and whatnot who consciously who you have kids with to some extent there's much more control over it if you look at populations

with less contraceptives well then you start to see rates of 5 percent 10 percent uh among the Himbabwe 48 percent really high rates of extra-pair paternity so is some evolutionary psychologists have said oh dual mating isn't true because it happens at such low rates and it's like well first reconsider that you know two percent number in terms of the 15 percent

of women who have a fares reconsider it as a hit rate as opposed to an attempt rate and then also reconsider it in the sense that that's not nothing over millions of years right from an evolutionary timescale but also it's not necessarily relevant uh to our understanding of our ancestry given that we have contraceptives now and we really didn't then what about men's

motivations what did you learn from them yeah men's motivations um I guess I actually do want to say one more thing on the on the iq point because I think that there is a and then I'll talk about men's motivations right after I'll just go straight into it I guess one issue from outside evo psych is this idea that the dual mating hypothesis is somehow or the mate switching

hypothesis or any of these that it's somehow sexist to talk about the evolved psychological influences on human sexual behavior the first thing that I would say to that is just that the evolved psychological influences on men's sexual behavior are also very unfavorable right the portrait that you can paint of men's behavior using evo psych is downright dastardly

right it's full of deception uh men's affairs just you know as much variety as possible you know completely emotionally detached we've talked about the seduce and abandon strategy all of this is very ugly and it's important that we have if we want to reduce ugly behaviors it's vitally important that we have a good understanding of what's actually happening instead

of deluding ourselves that other influences are at play more you know comforting ones another thing is that the primary advocates for the dual mating hypothesis I mean the senior author on our paper Candace who you've spoken to uh she has a gender studies degree uh everyone on our paper is a feminist right like we all we all we all believe in you know gender egalitarianism

and you know some of the chief advocates for dual mating Elizabeth pills worth back in the day Marty Hazelton even today these these are women and feminists who are interested in this topic so the kind of outside evo psych view that it's like oh this is like some kind of like anti-woman agenda now we're just interested in what's true what's false and we're trying to

take the politics out of it as much as possible so you can just buckle down and do good science yeah I think we're talking about our motivations it's certainly um it doesn't paint women in a particularly flattering light but we're talking about infidelity like yes you know you were talking about and most women don't cheat but what this what this does show I think uh

if you do get pushback more pushback saying this is unfair this is you trying to control women's sexuality this is you painting them as McIverlian and all the rest of it I think that what that betrays is the typical social expectation and interpretation of women's behavior which is that sexually women are not the protagonists that they are almost always responding

it's actually low key quite a sexist perspective on women that they don't have agency to go and chase down a new partner you know it's the same people that will tweet uh you're too good for him bay you know like remember remember your value queen whilst also saying no no no no women are never the ones that initiate women should never be the ones that so on and so it's such

a it's such a low like it's such a midwit take from people that pretend to be egalitarian between the sexes it's not it's not it's like the soft bigotry of yes male expectations it's it's yeah it's it's it's it's it's so so based such a good point it's incredibly patronizing how everyone's happy when you talk about men's evolved psychology but then as soon as you talk

about women's it's it's it's it's almost as if the whole story is about men and this is something that I see a lot in kind of public discourse is that you know if you label everything as you know the patriarchy let's say well then you're basically saying that men are the only ones with their hands on the wheel and that's a pretty patronizing view of women our lab views

women and men both as active sexual strategist and that's a much more ferv I mean politics aside it's just a much more accurate view I mean it would be weird if if women weren't active sexual strategists but but also you know I think it's even less flattering to just say you know to just pretend that women are always acted on as opposed to active agents in their own rights

actually but yeah I mean I think I think I can't tell if we're being woke or anti-woke here or or we're doing something I'm sure that will be accused of being both yeah the last five minutes of our conversation is gonna be a Rorschach test online so I'll see dude I've been using that all the time I've two memes that I'm yet to write into existence one being an ideological

Rorschach test so a good example of this was Trump getting shot in the head that was an ideological Rorschach test that was either on one side the Dems trying to take down the candidate that was going to win through purposefully stopping the secret service from protecting him or that was Trump attracting crazies in a world where he's enabled everyone to have a gun

that he was just pick and the other one the other meme being a thinking in super positions so you have these two worlds that both exist at the same time and they collapse down into one and it's interesting to see you know we talk about okay so you saying that women don't have agencies actually well no of course they do of course we need in fact they need to have more it's

that right okay so you're saying that they can make choices when it comes to their own infidelity yes and you would surely expect that they would make strategically prudent choices I mean what's the culpable they're going culpable for this thing yeah it's so it's so funny okay men's motivations what did you learn yeah that was those that was a rich segue this now

this now feels relatively this now feels relatively lightweight by comparison but again top male motivation is relationship to how to dissatisfaction again but it's that relatively comparatively more frequency that comparatively lower frequency that's the sense that I'm using relatively here so about a third of men about 30% said that they were dissatisfied

about 16% so significantly more than women said that it was because they had an attractive affair partner and about 14% of men said that it was motivated by sexual desire and here again I just want to note that the qualitative data is qualitative and so it's subject to these reporting biases it's subject to these interpretation biases are we really meant to believe

that only 14% of men's sexual affairs are motivated by sexual desire I mean that surely it was part of it for much more men it's just that it's not particularly flattering or self flattering to talk about those things and so men are going to be wants to report that at a lower rate because it seems a little inappropriate that would be my interpretation of that but it is interesting

that there's a sex difference there and that actually was something that's consistent with the mainstream evo takes on infidelity that men's infidelity is somewhat more sexually driven directly sexually driven in women's infidelity because for men's infidelity the only benefit really is actual that's the mainstream take it's not my take I think that men

cheap for a lot men and women both cheap for lots of reasons some men in our sample were made switching some men in our sample had an affair because they wanted a new girlfriend that happened at a similar rate to women as well what was the rate of men saying that that partner wasn't invested I think it was 5% right interesting we're going to get on to talking about jealousy

shortly but just to kind of round this out what are the what are the exoplanets the unspoken ghosts and sort of potential orbiters of infidelity hypotheses is there anything else that's still lurking out there in the ether that isn't dual mating made switching oh yeah yeah multiple investors is the is the elephant is the has to be the elephant in the room I mean there's

a few elephants in the room one that I think you've talked to Jeff Miller have you yeah yeah yeah actually I've seen clips so Jeff Miller had a hypothesis that didn't really get hardly any attention which is that part of the affairs that we have are to gain information right to calibrate our own mate value to gain skills in seduction and that theory is largely been brushed

off but it did pop up quite a bit that I can actually check the percentage here um it wasn't nothing you know about one in 20 people said that they were cheating for some variety of information acquisition right what like so you mean information acquisition are they fucking spies what's going on so so for example one woman said that she wanted to uh basically wanted

to obtain skills in seduction she didn't phrase it that way but it was like I wanted to be able to do this I wanted to have this ability and so that's kind of a that's a reason for infidelity that's strategically legitimate where it's like look I don't really know my own mate value or I don't really know how to get guys or I don't really know how to get girls and that's a very

important life skill it's going to be important throughout my life let me go work on it right on the side that I wouldn't expect it to be the main motivation for infidelity but it's a motivation you can imagine someone who is you know let's say a college student they're in their first big relationship they're halfway through college and they realize huh I actually

don't really know what I'm doing still dating and I'm going to have to date my whole life right until I get married at least so let me go get some skills here I said this about uh people who get into a marriage with the first person that they ever have sex with uh and it's kind of like being with your first ever therapist I'm yeah doing therapy at the moment in a lot of people

it's first time I've ever worked with someone for this long in person etc people go what's your therapist like I go I think she's great but I really know because I got nothing else to compare it to yeah and it's it's kind of the same with that and I suppose you just don't know could I do better could do any better is this really the best that I could do yeah so there could be

some mate value calibration that comes from engaging in infidelity to some degree multiple investors is worth talking about because that's most of the theories that we've been talking about for women's infidelity have been quote unquote quality driven theories the difference is what qualities are being searched for so again mate switching is best overall

whole package whereas dual mating is the best combo deal but both are quality motivated multiple investors is a very interesting hypothesis it seems to be the primary explanation of infidelity among the himba of Namibia and it's essentially that if a woman can't get enough resources from one man well then she can obtain supplementary resources from additional

mates on the side so this wouldn't be a quality driven hypothesis it would be a quantity driven hypothesis it's just that the quantity or not necessarily quantity driven but to but it's quantity of resources and that could translate to quantity of mates I would have to talk to Shels about it but it's a very interesting hypothesis and I think it does happen we didn't

find a lot of evidence for it in our sample unless you take the uninvested primary partner as evidence for it like oh this guy's not invested in me let me go get some investment somewhere else but very anecdotally I have at least heard of you know people having you know maybe a kind of sugar daddy character on the side who it's like he's not particularly attractive but you're

but you need you need to pay rent at the end of the month and so this is something that something that you engage in so I don't think multiple investors should be expected to be at high frequency in high SES countries and in high SES individuals but in situations where resources are scarce that could be very well be the main reason that women have affairs to obtain additional

resources do you know the wizard Liz do you know that YouTube channel no right so her channel's huge but just has not come across my radar until recently she's got six and a half million subs on YouTube huge hugely engaged Instagram as well and she regularly does videos basically explaining how to get the princess treatment which is how to make your man a man pay for your

entire life pay your bills by your car pay your tuition ensure the young look after treat treat treat you like a princess and if I was to speak to her I would very I would be very very interested in asking sort of what are the motivations for that what do you think about using multiple partners like really trying to dig in she's like super duper famous and it's you know

it's kind of tangential to this sort of boss bitch thing but it's done in a very different sort of a way because obviously it's it's not focusing on financial independence and not needing a man it's a more uh someone say McIvelian manipulative version of this to get the guy to pay for those things uh for everything that you should be showering gifts that it's very important

that you're showering gifts that you should set the tone she uses I was watching this video from a yesterday she says that you should lie to every new relationship that you're in and say that the guy in the previous relationship spoiled you because men will only work as hard as they feel like they need to to beat your previous boyfriend so uh basically if your last boyfriend

uh beat and abused you and never cared for you your next one will just think well if I just don't beat an abuser then I'm better so it's a very interesting like super interesting fast and I'll send you some of the videos once we've finished up um yeah I'll be interested to see if uh men start taking on that strategy because it's this is the first period in history where it's

viable to be you know a boy toy or a dude I'm an aspiring fucking trophy husband have been have been for a very long time unfortunately you've got too much money for that I still have hope um I'm still hoping for an arrest to step out of somewhere um okay so what about the role oh how does this fold into your new sort of perspective on this how does this fold into the discussion around

jealousy about sex differences in jealousy about why men and women get jealous its evolutionary function etc well I mean this is what's funny is that the dual mating hypothesis is more consistent with the evolutionary psychology literature on jealousy uh I mean it's quite conspicuous to me but it doesn't seem to have been acknowledged generally it's something

that we've touched on earlier which is just that if so okay well for to give everyone the download if they don't have this information yet on average it varies the degree of the sex difference the size of the sex difference varies and it also varies what people care about right so there are plenty of cultures where everybody cares more about sexual infidelity or everyone

cares more about emotional infidelity but the general difference is that within a culture on average men will be relatively more concerned with sexual infidelity and women will be relatively more concerned with emotional infidelity and that makes sense if dual mating is the concern because men aren't protecting against a woman leaving them for another partner

they're protecting against the potential that they will be quote unquote cockleded right they they don't want they're they're more upset by sexual infidelity because men can be cockleded where women really at least not in the same way right and a euphemistic way maybe but not in a not in the literal sense on women on the women's ends we've talked quite a bit about investment

they're going to be chiefly concerned or not chiefly necessarily but they're going to be more concerns than men with losing investment because women's investment is more obligate men's investment is more not morally but pragmatically optional and so that's really the landscape in terms of sex differences and jealousy it pops up everywhere it's looked for and I

will note though that some people have taken it some people have have exported this evscike finding and said that like oh women women don't care at all about sexual infidelity their main concern is emotional infidelity as long as it's just sexual it's fine that's not what that that doesn't pop up women are very upset by sexual infidelity and then also in the other

end men are very upset by emotional infidelity it's just that relative to one another within a culture you'll generally find the difference in that direction and this makes sense under a dual mating view because men are paranoid about getting cuckled it and then it also makes sense from a traditional kind of what what women stand to gain from relationships in the view

that it's like well if he is invested in her emotionally then he might go off and raise her kids instead of mine and maybe he's not invested in me a men have paternity uncertainty women have investment uncertainty that's how it summarizes it a consequence of this being accurate dual mating being the leading infidelity theory would be more men being cuckled it ancestry

is that right yeah and I think it's a very reasonable to think that that happened quite a bit I mean if you look at even even like rural American populations I've seen higher numbers like close to 10% in terms of estimated I really like if contraception is low and infidelity is high you're going to get a lot of men raising kids that aren't theirs that doesn't happen a lot

in the modern in modern America in modern Britain in modern Australia where there's contraception and strong social norms against infidelity we don't really see we don't really see a lot of that so it's not really something to worry about in a modern context but an ancestral context I would say that this would be a real worry I will also note that there's a great new

paper relatively new paper from again Birkshell's called the cuckoldry conundrum which is just pointing out that sometimes you know our conception of cuckoldry does isn't necessarily exportable in the sense that and this might sound strange but sometimes you know that a child isn't yours but it still makes evolutionary sense to invest in them so for example

among the himba there's tremendous status to be gained and social cloud from being a good father to your wife's a fair partner's children so that's pro social in some ways Jesus yeah so it's like you would be because and and you got to keep in mind that you know they've probably played both sides of the field here so they've probably got they've probably got eggs and other

nests themselves to use a metaphor and so it's kind of it's kind of in everyone's best interest to be like you know let's just invest in the kids that are in our next three for all it's a pull what this is kind of like the human equivalent of the wife female chimps made with multiple males because the risk of infanticide gets reduced because each male is uncertain about whether

or not that child might be his I'm not sure about even true but it seems to me this seems to be a more kind of yeah socially enforced equivalent of that yeah I would call that a yeah I would call that a tangentially related hypothesis for sure I don't know how high and this is something that you should talk to Martin Dalley about actually as because he's his Cinderella effect

book is just the truth about Cinderella so yeah that's such a fun one about infanticide in humans I say fun oh my gosh don't clip that roof with but yeah interesting how it I really did mean it when I say I don't care how gross the theory is I just wanted to do but I don't know how much infanticide has actually played a role in humans but it's kind of funny and this actually

relates back to the political conversation we were having earlier is that some of the initial theories from Sarah Herty on women's infidelity in humans were related to paternity uncertainty and hilariously given that you know this is something that Louis Bichaud pointed out to me which is that you know in the 70s 80s and 90s these findings on women as sexual strategists

dual mating paternity uncertainty creation these sorts of things they were championed at that time as feminist ideas and pushed back upon by right wing people who wanted women to you know they had this archaic view of women as passive and you know not engaging in the sexual marketplace as active agents and now today we have the complete political reverse where it's

the same set of scientific findings but it's the super feminist groups that are saying oh that's just not true da da da da they're kind of acting like the old right wingers and it's the really misogynistic groups such as you know the tail end of in cells and and such who are holding up these same findings and saying they're great so I think that that's better evidence

than I've heard for anything that uh these facts facts are facts are neutral and if you have an agenda you can collect a set of facts and spin them in a way that fits whatever agenda you like the same findings that today we call our sacks we call sexist were originally you know champions by by feminist scholars and that's that's just the way the cookie crumbles well the the the whole

shoe is very whole shoey and it ends up being a a total fucking circle eventually yeah it's more like a merry go round in the history of this debate the same the same sexual findings that were considered liberal are now considered conservative and if you give it another 20 years it'll probably flip back back around meanwhile we're just going to keep our heads down

and try to figure out what's actually going on what are the predictors of infidelity how can you tell if someone's going to cheat okay there there's actually there's actually a long list here the most obvious one would be have they cheated on a past partner once a cheater always a cheater this lines up with our folks' psychology it's not exactly true in the sense that many

people cheat on one person and then never cheat again but it's it's true enough let's say so there is one longitudinal study from Kale and Op that found that if someone had cheated in their last relationship there were three times more likely to cheat in their next relationship you got any idea what the base rate is oh the base rate of infidelity yeah it's difficult

to find in dating couples i'll say two things that i'm quite confident in i would say that about a fourth of marriages will encounter infidelity at some point in their lifespan and i would say that about half of people maybe a little more than half in man a little less than half in women but somewhere floating around that kind of mid-range not like a super majority or super

minority will cheat on somebody at some point but that doesn't mean that they'll cheat on you specifically in one relationship so for example there are plenty of people who you know cheated on their college boyfriend or college girlfriend and then they never cheat again for the rest of their lives but given that most people have several relationships and also given

the data showing that most people report getting cheated on by somebody at some point i would say that the inverse is also though that it doesn't logically necessarily follow i would say that it is likely that about half of people will cheat on somebody at some point but i would love to see better data on that unfortunately the really good data has been collected on marriage

Yeah uh extraper interest we are naturally quite sensitive to extraper interest we notice it so people tend to notice if their boyfriend is constantly checking other girls out that seems to predict infidelity empirically i believe there's even a study where they tested you know how long a man's eyes lingered on other women and that was predictive of infertility

which is kind of funny and you know extraper flirtation that sort of thing i would i would be attuned to that there are people who are let's call it laser focused on their partner and then there are people who you know you go to the social event and they just want to they just want to talk to talk to all the hot guys or all the hot girls and they they that kind of thing that probably

doesn't doesn't go well narcissism is another thing to look out for that's another thing that i think people find quite intuitive and a general history of and i don't i don't say this in like a loaded way but a general history of promiscuity i would say it would be something to look out for like if you're if you're a woman and you're choosing between two guys and one guy

he's slapped with over a hundred women he loves going to the club he loves having one night stands he rarely has long-term relationships and the other guy has had like too long-term girlfriends and has never had casual sex if you're choosing between those two guys which is more likely to cheat on you i think it should be obvious but it is statistically backed as well

that the guy who has the more of a history of monogamy is going to is going to be more faithful in practice so that i mean i've given you like five things there so i think that maybe four i'm not sure i that that's quite a bit i seem to remember a line from one of david's books maybe the evolution of i can't remember um where he said that the single biggest predictor of extra marital

sex is premarital sex that's probably true that's probably true i love that line i'm stealing it but it's uh i'll have to check it yeah i just wonder i wonder how true that is i wonder whether it's whether it's the case you know is it is it just sociosexuality all the way down oh yes such a driving force that the person who wanted to have a novelty in their teens and in their

twenties um you know how much of that is setting a particular type of habit you know damaged goods how much how much are you damaged goods how much of you've set some sort of lifestyle routine versus how much of how much is this like a natural outgrowth of you and your nature as a person you know what i mean yes i completely agree i think that it is it's possible i mean it's

i don't find it completely implausible this idea that it's like if you practice having one night stands over and over again throughout your twenties maybe in your thirties it'll be hard for you to not do that when the opportunity arises uh but i also think it's plausible that as you say and this would be my this would be what i would think is that it's sociosexuality

all the way down so it's like if you want novelty and you're just holding yourself back from it i'm not sure that that actually will maybe the ritual of doing that will help you in a marriage but maybe it won't also maybe you want those things you want to be sexually unrestricted but women just don't like you and so when you're married the first time that you get the opportunity

maybe that's the first time that you take it as well uh so i would say that if someone is i think that yeah it's kind of you know human seem to exist partially on this spectrum and it's it's a construct but it's a useful construct of socio-sexuality some people are quite let's say unrestricted they like to have sex without love they like to have sacrilegeual sex and some

people are quite restricted and the people who are more restricted the people who are you know who don't have sex with people who don't love them the people who would feel you know uncomfortable getting naked in front of a stranger those people are probably going to be more faithful to you and i think i think that's pretty reasonable and i think you know that for all

the internet discourse uh i know that every podcast i want to put like a moratorium like a ban on body count because i've talked about it before so many times but yeah i would say that body count is a kind of a dull proxy but it probably is a proxy for likelihood of committing infidelity at least in the studies that i've seen yeah i suppose the reason the body counts uh an interesting

discussion the reason that it comes up so much is it's such a uh low resolution rough hue and signal in the same way as saying your bank account shows how hard you work mmm you know it's just it's this sort of odd singular figure that you can compare everybody has one everybody everybody has one everybody has a bank account how much money's in your fucking bank account

how many people have you had sex with yeah i would say that it probably isn't predictive i mean i think there was once actually i won't quote it because i don't i don't remember the exact stats but you know like i think it's pretty intuitive that if you're if you got one person who's only slept with one person before you and another person who's slept with a hundred who's

more likely what they're gonna cheat on you with the third person they've slept with or the one hundred and first you know i think it's pretty intuitive what are some of the common signs that the person is cheating signs that a person is actively cheating i mean a lot of these aren't literature backed but you do hear them from you know relationship counselors and relationships

psychologists and things like that uh i would say that in i don't think that you know you should be i don't really have prescriptive claims in my personal life i i wouldn't really want to be in a relationship where everyone's you know snooping on each other's phones all the time and accessing each other's technology but conversely anecdotally you do see it a lot where people

who get cheated on they're they say that their partner became very digitally secretive very protective of their phone right they leave they go to the bathroom leave the room and they are sure to take their phone with them right never leave their phone unlocked never let you use their phone for any reason i would say that that would be something that would be somewhat i

would say that that would be somewhat suspicious i suppose there are plenty of reasons why someone might be digitally secretive that aren't infidelity but it's also hard to imagine carrying out a full blown affair in a modern context without keeping digital secrets that would it that would be very stone age in in nature um i would say that yeah i mean a signs that they're

actively cheating are much more difficult because we don't have as much research on it um well by virtue the people who are actively cheating are trying to conceal it so who's going to who's going to you know below the tom cruise mission impossible mission whilst it's still underway yeah exactly so yeah yeah do you want to take part in my study that'll completely

you know expose you to unnecessary risk yeah in your secret operation but i would say that cautiously millions of years of evolution has prepared your brain for this moment of you know detecting partner infidelity potentially maybe maybe it's only tens of thousands of years it depends it depends how deep monogamy goes in our lineage but point being i would say

that trusting your gut to some extent is probably wise if you think something's fishy there might be with the caveat that you got to look at your personal history if you know that you're someone who's just morbidly jealous you're really oversensitive to that sort of thing then play a cautious hand i was going to say this thousands of people right now who like vindicated

the people who are adamant at all times there's something's going wrong there was this interesting study that i saw on sypost the top four behaviors that signal commitment within relationships on social media number one deleting dating apps number two ignoring flirtatious messages number three indicating relationships status online and number four unfollowing

potential alternative mates research has found that individuals with high attachment anxiety reported significantly higher levels of discomfort worry and jealousy when imagining their partner interacting with an attractive alternative on social media disconfirmed that such scenarios are particularly distressing for anxious individuals interestingly

the partners high commitment behaviors on social media successfully increased perceived partner commitment and the perceived devaluation of alternatives regardless of the participant's attachment style however these behaviors did not significantly enhance feelings of security all relationship satisfaction for anxious individuals as hypothesized

this suggests that while explicit commitment signals are important they may not be sufficient to fully alleviate the deep-seated insecurities and fears associated with attachment anxiety yes i mean that that's very cool and also i would say that the you know it's it's it's it's modern but that doesn't mean that it doesn't have some evolutionary roots this broadcasting

that you're in a relationship on social media what it reminds me of most is i i spoke to one of if not the leading experts on gibbons on my podcast species and we were discussing monogamy and gibbons so gibbons are our closest socially monogamous relatives and one thing that they do is they sing duets together and part of that function i mean it's got many functions

but part of that seems to be to broadcast the pair bond to basically say they said the the gibbon pair will sing a duet say hey everybody just so you know we're still dating it's the relationship status update on facebook yes exactly and so whenever i see someone just kind of put up you know their their girlfriend posts them and then they share the story or vice versa it's

kind of like it's kind of like you're doing a gibbon duet in the sense that you're both signaling hey everybody alternative mates were in a relationship so there's no uh and and we're doing we're doing well uh so that sort of thing it it has its roots i would say in a very basic evolved desire even if the behavior itself is not evolved obviously we are there's no selection on instagram

posts at least not yet yeah that would be sick but um yeah what have you learned about what counts as cheating uh there's that there's that there's that there's major variety i mean i mean it's hard to know because a lot of this is from the gray literature but some i mean if you're in an open relationship for example even sleeping with someone else is not necessarily

cheating so and then on the other end some people who are in very uh let's say sexually restrictive relationships would say that pornography is cheating or that even fantasizing about other people is cheating or that light social flirtation with other people is cheating and there's a huge spectrum as to what's considered cheating what's not what's considered

just disrespectful versus full blown affair for what it's worth our study only looked to the study that we spent the first uh half hour or so discussing today we just looked at sexual affairs and it's possible that if we you know women are more likely to engage in emotional affairs than men based on the existing data that we have on that subject and it's possible that purely

emotional affairs are more geared towards made switching that would make sense towards to me oh that is interesting yeah like non the what is the function of non sexual emotional affairs like where a woman is you know daydreaming about her coworker crush but isn't actually acting on or man you blowing my mind you blowing my mind because this you chose a particular

bar to classify infidelity and by design that bar would lend itself toward the dual mating hypothesis more than it would lend itself toward the mate switching hypothesis that is correct however I will also say that cheeky cheeky it's not cheeky I wasn't rooting for the dual mating hypothesis if anything I was rooting for the mate switching hypothesis but tried

to you know stay as emotionally neutral as possible I was surprised by the results and I'll also say that to be to give the devil what's do advocates the mate switching hypothesis they do think that the they or they did think maybe maybe this research will change their minds that the primary function of women's affairs sexual affairs is to obtain a new mate so the sexual

affair test I think was a fair one because look we're looking at extra pair mating we're not looking at extra pair flirtation which can have you the more functions I mean sometimes you'll flirt with someone who's not your partner or one will flirt with someone who's not their partner just because they want to be more popular at work or they want to get a raise or they

want the airport they want going through the airport to be slightly smoother that's literally I was about to say if I want a second lotus bisque off on a delta or something I'd better hope that it's one of the female air hostesses that comes around because if it's that miserable luck in bloke with a beard I've got no chance if I'm flutter my eyelashes in the right way

at some lovely lady then maybe I get a second biscuit yeah I mean I'm just I'm so fascinated by that by what constitutes cheating and the sort of emotional infidelity versus sexual infidelity it's a term we haven't used yet but monkey branching sort of for more relationship to another lying from a switching yeah where you are sort of dipping your toe in just how invested

is this person just how funny is this person just how good are the do you how good does he smell yeah before we get to how good of a lover yeah before we get to that so I'll ladder up all the way um before I get to that one and uh yeah it's also what I suppose the thing from a operational perspective for one of a term that makes it sound less like a military fucking undertaking

it allows more culpable deniability for anybody did you sleep with him look I haven't even touched anybody darling I've never touched anybody it's like well that's not that's not that's not much safer yeah it's a much safer yes yes yes an emotional affair is much safer and so you're insulating yourself against the costs while you're engaging in it I think that makes

a lot of sense I will also say that one of the strengths of the mate switching hypothesis is that because it it is about sexual affairs it's also about emotional affairs but because it is about sexual affairs is that it acknowledges something that's true that Helen Fisher actually said this to me she said you learn a lot about someone between the sheets right there's

a lot of mating relevant information that is obtained through having sex with someone how conscientious they are how much they care about you versus themselves uh how athletic they are you get a lot of information is cheating heritable have you looked at that the behavioral genetics of cheating yeah I mean everything's heritable I'm not I'm not a behavior geneticist

uh but there have been studies on the subject and it shows that you know uh I mean genes code for proteins and regulatory molecules that build and operate your brain it would be bizarre if genes had no influence on any behavior like for a behavior to have zero genetic input would be peculiar and there hasn't been a ton of research on this but there have been you know some

twin studies some candidate dean gene studies and candidate gene studies are always a little a little more questionable but the twin studies I find that study does I'm again I'm not a behavior geneticist I do find that study designed quite persuasive and those indicate that yes cheating is heritable uh hey talking to some uh gene embryo selection uh imagine if he

could I'm gonna I'm gonna select for a scoundrel chad of a son I'm gonna have him just absolutely decimate stocked in on tease in the northeast of England well the reason though the reason that that's I mean that's very funny but I suppose the reason that that is and the reason that I think I don't know why embryo selections coming up so much but I guess the reason that I

think that this whole project might be a little unlikely is that the things that the genes that affect ones propensity to cheat it's not going to be one cheating gene it's going to be thousands of genes that each do hundreds of different things right it in all likelihood at least by my understanding it's going to be like you know the influence of one gene that has a tiny

effect on risk taking propensity another gene that has a tiny effect on socio-sexuality another gene that has a tiny effect on honesty right they're just all these genes that have tiny effects on things that are good in some contexts and bad in others and so in order to genetically adjust someone's probability for like what does what does someone who has a zero is zero

percent of the cheating genes look like maybe they're all of the maybe they're super boring yeah um have you seen this new I think it's Jacob or Jacob fought examining the fraternal birth order effect and sexual orientation insights from an Eastern European population Jacob fought and colleagues examined the fraternal birth order effect why by men with more

older brothers and more likely to be gay this seems at least slightly relatively robust analyzing data from Croatian Slovakia they find that the fraternal birth order effect exists for lesbians too women with more older brothers are more likely to be lesbian strange I mean so not my area but very interesting fascinating dude I thought that was so so I mean you know

I had Dr James Cantor on the show and he's just he's spicy and lots of people really don't like him but I for his area uh parasexuality is that it the one where it's like all sorts of weird sexualities he is he's just the best and uh yeah he he taught me very much he's he's gay and he taught me a lot about the birth order effect but the fact that it occurs for lesbians too I thought

yeah a bit a bit confusing and also I I would just love for there to be like a really this is something that I don't know if we'll ever get it because it might not be adaptive but it would be so cool to get an adaptive story of homosexuality that works but at the end of the day it just matters what's true and I just I haven't heard I haven't heard an evsite story that the only

one makes a lot of sense and two actually has good data behind the car's not my area I can't give you the data but I can give you one that's got a good story so um if as a but it only works as guys it really doesn't work as for females and this female thing throws a huge spanner in the wrench uh the works of it which is if you have had multiple males go through the same woman your

mum it is likely that the sex ratio is going to be skewed toward men which makes it less likely that you as a man are going to be able to find a female mate and so you become a kin helper essentially and invest in your brother's offspring I think so yeah I mean that's again very interesting doesn't fit with this new finding on absolutely totally fucking vital like why would the lesbian no no no no we

need more of you like we really the men all of your brothers well maybe not your brothers yeah it seems more of a it seems more of a I think that it seems like more of a spandrol like that would be the sort of hypothesis where it's like there's selection on like I've heard again this is so in my area but you know I've heard stories about maybe that maybe certain strong selective

biases uh select for genes that also you know at a low dose they're they lead to certain things that are very selectively advantageous but if you get a high enough dose of them then you become purely same sex-tracked and the buck stops there um I guess my favorite hypothesis that might have been true in our ancestry just doesn't seem to be particularly true now would be

this idea that would be this kin selection idea that it's like in some circumstances because we see this in other animals in some circumstances it makes more sense to invest in your kin's offspring than your own offspring because they share 50% of your your kin's born basically to be an alloparent and you've got born to be an alloparent early warning sort of detection system

about the sex ratio and then downstream of them okay so I met an evolutionary biologist who liked that and he called it I don't know if this is his name but it's such a funny one um he was gay and he called it the the rich gay uncle hypothesis and I was like huh it kind of is true and I looked it up and it's like oh yeah gay guys do tend to make more money and they do tend to invest

a lot in their nephews I like this is kind of cool but it doesn't seem to be it doesn't it's again it's just hypothesis and I actually don't think it's true I think it's more likely that not everything is explicable by evolutionary side yeah but it's I mean I wish it was fun which is which is which is that's the root that's epsych's biggest hurdle is that it's so fun to come

up with stories that uh we tell too many and so uh you have to be very conservative with your hypothesis and test them rigorously we've spoken about uh repeat um uh people that are consistently being cheaters uh the culprits what about people that are repeatedly victims is the such a thing as a repeat infidelity victims some people always get cheated on other people

managed to sail through completely smooth if I'm remembering correctly in the Kalanop study people who were cheated on in their last relationship were twice as likely to be cheated on in their next relationship and some people hear that and they think of it as like oh with it that's just lightning striking the same spot twice oh my gosh but the truth is is that lightning

does tend to strike the same spots because there are things that affects the probability of where lightning hits so this isn't victim blaming but it's possible that someone is very low skilled in make guarding let's say uh they just don't do that effectively and so they consistently get cheated on or another thing like we often see that people are attracted to narcissists

we know that narcissism covaries with infidelity and so if you're someone who finds you know super cocky guys really sexy well you're gonna pick those guys over and over again and then you're gonna end up picking you're picking a trait that covaries with infidelity and so you become repeatedly victimized to it again not victim blaming just stating the reality

that sometimes people's strategic decisions have an influence another possibility though is that this is based on self-reports right did you get cheated on in your last relationship did you get cheated on in this one and it's plausible to me that some people are too suspicious and over report infidelity or some people are just really good at catching cheaters

like they've got a skill there and so you know everyone maybe the rate of getting cheated on is relatively evenly distributed between the two groups but the group that gets cheated on a lot are constantly catching it I mean and you know it's it's plausible to me that you know if you're someone like myself for example who wouldn't go through their partners found right

I would just feel like that was like a gross thing to do I mean I'm I can certainly imagine circumstances I'm not gonna say I've never done it or that there wouldn't be circumstances where I could but just that it would generally that would be something that I would find very aversive there would need to be some really legitimate reason well then maybe I'm more vulnerable

to infidelity but I'm also just more vulnerable to not noticing it so there is this effect where people who get cheated on in the past are more likely to get cheated on in the future and people who haven't been cheated on in the past are less likely to be cheated on in the future so winners keep winning and losers just lose more right that seems to be the case but it could be

a detection bias it could be a as you like to say a skill issue just not good at skill issue man yeah not good at detecting it or not good at picking mates or you know but it's an interesting phenomenon I'd love to do more research into it but it's not my research so that's fascinating yeah it's the consistent themes that you find throughout your life if they continue to

come up have to have something to do with you maybe it's you yeah it has to have something to do with you and maybe it is that you go you're unbelievably good at detecting but given that not everybody cheats all the time maybe it's that you're good at picking cheaters maybe that's your skill I think the most likely explanation is that you're attracted to traits that co-vary

with infidelity so if someone says to me why does everyone cheat on me the first thing that I would ask in a less callous way why do you keep dating cheaters yeah what is it the predicting yeah what are you attracted to that's causing this problem because if you think narcissistic bad boys are super hot well problem solved maybe not and if you're you know sure yeah miss

yeah Sherlock Holmes over here have I've solved it and vice versa for man if you're attracted you know if you're a man and you're attracted to really dark triad kind of sexy flirtatious women you know maybe maybe that maybe that's maybe maxing out on that and it could also be it could also be a prioritization issue so let's say you're the sort of guy who puts physical

attractiveness above all else you don't pay attention to personality it's just who's the hottest girl that likes me that's who I'm gonna date and then it's like why do they all cheat on me it's like well maybe you should have you know considered shared values you were selecting you weren't selecting for loyalty yeah you didn't select for loyalty so bit of a skill

issue but we won't victim blame too much what does this new study at this new insight how does it inform your perspective on how natural and natural infertility is ancestral mating strategy sort of monogamy versus monogamy versus monogamy versus cereal monogamy versus polygamy does that does it sort of adjust your worldview at all?

no but I'm so glad you brought this up one thing that I will say is that again I want to emphasize that my study is just one study and I look forward to more research hopefully research using the same paradigm where we look at actual people who have had affairs and that try to investigate women's infidelity more and then also that even though the top line conclusion is a you

know a pre-registered win for the dual mating hypothesis best case scenario and worst case scenario for mate switching we also found that some women mate switch and women cheat for a variety of reasons including obtaining additional resources getting revenge etc how does it affect my view really not that much the it definitely affects I thought that mate switching

would be much more common and I found David bus's arguments very eloquent and persuasive for the mate switching hypothesis and I'm a huge fan of David bus so I I thought that maybe this would be a win for the mate switching hypothesis I was kind of surprised it wasn't so I guess it changed my view in that sense but it didn't change my view as to whether we're naturally

socially monogamous mammals because most socially monogamous mammals engage in extra-paramating and most have some degree of extra-paraportunity so the idea that we socially monogamous mammal also engage in engages in extra-paramating and also has you know some degree of strategic evolution in the context of extra-paraportunity neither of those things

were particularly surprising a lot of people hear the word monogamous so the way that the way that folks at home use the term monogamous is different from the way biologists use monogamous generally when we talk about monogamy we are distinguishing between genetic or sexual monogamy and social monogamy and most species that are labeled monogamous are only socially

monogamous so there's some degree is you know plenty of them don't cheat but many of them do one example and this would be a very unethical study to perform in humans our closest socially monogamous relative the Gibbons there was a study in the 1990s the scientist named Breikard he or he or she I can't remember they he they went out into the field and just watch Gibbons

having sex and tried to tabulate how often was it with the primary partner and how often was it cheating and a full you know 11 to 12% of the time it was not the primary partner right so that's not that's not 11 to 12% of Gibbons cheating that's that number of Gibbons that's Gibbons having sex with other partners at that rate so usually with the primary partner but very

often times not so some people are going to hear this and think naively because they don't have and and this isn't you know this isn't there's nothing wrong with this but because they don't have the kind of biological anthropology context they might think some people might think oh Mackin's infidelity research suggests that humans aren't naturally monogamous

I would say on the contrary it's completely consistent with us being socially monogamous and given that again most women do not execute a dual mating strategy in this way most women get their genes and parenting from one partner both in terms of their psychology and the cycle psychological mechanisms undergirding their behavior and in terms of their actual behavior and but in any

case they're they're gonna some of you are going to hear this and think oh this means we're not naturally monogamous it's consistent with us being socially monogamous it's just it's just a question of how sex women are we are so fascinating stuff man it's so interesting and I think I'm I'm gonna like throw a little bit of money into the ring that there's something

missing with the way that the studies are being done for ovulatory shift that it seems to unlikely to me that we could have all of these converging and it would be so useful for ovulatory shift to happen for it to not actually have an effect because it seems to me that each time that it comes up it sounds really cool and it's this sexy explanation and then it doesn't replicate

or yeah there's there's something in the data that does whatever and it just to me seems like such an obvious mechanism for evolution to take advantage of you know the original pill the original the original pill the original contraceptive control for women concealed ovulation with behavioral change that occurs during that period of time no one knows maybe not even

her and it would just be I don't know I also I feel the exact same way in the sense that I think that may be more sophisticated study designs that look at partner qualities and look at relationship qualities as mediators maybe those end up validating the ovulatory shift hypothesis but I will note again and emphasize that the dual mating hypothesis does not need ovulatory

shifts for example one might intuitively think that in monogamous relationships right fully sexually monogamous relationships it would only make sense for a woman to have sex ovulation because sex has risks and that's the only time she can get pregnant but instead we see that there are benefits to having sex outside of the cycle outside of that part of the cycle

and it's possible that there are benefits to having sex with ones a fair partner outside of that part of the cycle as well in terms of seduction in terms of may acquisition I mean it's funny I was talking to a couple of ovulatory researchers at a conference and one of them said offhandedly but it was so clever they said we'd have more success testing a weekend weekday

shift hypothesis because so much more cheating happens on the weekend versus the weekday and that really puts the that really puts the cycle shift effect sizes into comparison hmm it's not like it's not like humans are werewolves and depending on what part part in our hormonal cycle there's like noticeable changes humans part of being human part of the defining

characteristics of our species or the suite of defining characteristics is that we exhibit remarkable sexual stability across the cycle and even if we exhibit dual mating it's not inconsistent that that stability translates to infidelity hell yeah mac and murphy ladies and gentlemen dude Chris Williamson I really appreciate you your works fascinating I

love the fact that you can communicate it this well and I'm excited to see what you do next I will be seeing you in Australia in only a couple of months time when I'm out there for my tour so are you good you still going to be there I've got tickets I have got tickets to your to your Australia concert of sorts oh yeah yeah I'm gonna come out and play the banjo so if anyone is if anyone

is going to Chris's Melbourne show that's that's it's gonna be I'm sitting in one of the regular seats it's gonna be it's gonna be a very easy opportunity to meet me as well I'll be doing an unofficial meet and greet that'll be in the in the aisle where should people go they want to keep up to date with your work what podcast all of the things where do you want it to go if you

google my name everything comes up my podcast is species the app that I have for couples is coupling and you know I've got a course on human evolution if anyone wants to I bought it going about those very good highly recommended I bought it going by it if you want to learn more about this thank you Chris and so you know there's a few there's a few ways to get more time with me

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