More intelligent men are more likely to value sexual exclusivity than less intelligent men. Does that mean that more intelligent men are more likely to be sexually faithful and less likely to cheat? Probably not.

In a previous post, I explain that one of the implications of the Hypothesis is that more intelligent men (but not more intelligent women) are more likely to value sexual exclusivity. Some tabloid newspapers have sensationally reported these findings with such salacious headlines as “Cheat-on-wives men ‘less intelligent’” (pardon the hideous syntax; it’s British tabloid), “Smart men less likely than dumb ones to cheat on lovers: study,” and “Intelligent men ‘less likely to cheat.’”

Apart from the sensationalism, and the confusion between “intelligent” and “smart,” which I explain in a previous post, are these headlines correct? Does the conclusion that more intelligent men are more likely to value sexual exclusivity mean that they are less likely to cheat?

If and were an entirely or mostly male choice, and it happened whenever and with whomever men wanted, then it would be reasonable to conclude that more intelligent men, who value sexual exclusivity more than less intelligent men, may be less likely to be sexually unfaithful than less intelligent men. However, as I have explained again and again, sex and mating among most mammalian species, including humans, are an entirely female choice. It happens whenever and with whomever women want.

There are several complicating factors here. First, more intelligent individuals – both men and women – are more likely to attain higher status and accumulate more resources than less intelligent individuals, at least in the evolutionarily novel environment of today. And women prefer men of higher status and greater means as their mates. Second, more intelligent individuals – both men and women – are on average physically more attractive than less intelligent individuals. And women prefer handsome men as mates, particularly for short-term mating (“casual sex” or “affairs”). Third, is highly correlated with height; more intelligent individuals – both men and women – are significantly taller than less intelligent individuals. And, once again, women prefer taller men as mates.

So, if you simply compare more intelligent men and less intelligent men, without statistically controlling for their social status, income, wealth, physical , and height, then I am almost certain that more intelligent men are more likely to have affairs than less intelligent men, not necessarily because they are more intelligent, but because they are more likely to have higher social status and greater resources, to be physically more attractive, and to be taller. If you partial out the effects of status, resources, physical attractiveness, height, and all the other potential confounds and correlates of intelligence, then, and only then, may more intelligent men be less likely to have affairs.

However, to the best of my knowledge, no one has examined the partial effect of general intelligence on the probability of having affairs, net of all potential confounds. So we need further research in this area to determine what effect (if any) men’s general intelligence has on their sexual behavior (extramarital or otherwise).

In fact, data from the General Social Surveys do suggest that more intelligent men (and women) are more likely to have affairs. The mean IQ of men who have had an extramarital affair is significantly (though only slightly) higher than that of men who have never had an extramarital affair (102.4 vs. 100.5). Among women, the difference is slightly larger (104.6 vs. 101.5).

The association between IQ and extramarital affairs remains significant, for both men and women, even after I control for , income, and social class, as well as race, age, current marital status, number of children, religion, and . The effect of IQ is much stronger for women than for men. It is not clear to me why more intelligent women are more likely to have affairs than less intelligent women. Interestingly, as is quite often the case, intelligence and education, which are positively correlated with each other, have opposite effects on extramarital affairs for women. While more intelligent women are more likely to have affairs, more educated women are less likely to have them.

Unfortunately, the GSS do not measure the respondent’s height or physical attractiveness, so I cannot control for them in the analysis. The National Longitudinal Survey of Adolescent Health in the US and the National Study in the UK, both of which do measure height and physical attractiveness, do not measure the respondent’s experience of extramarital affairs. It therefore remains to be seen whether the significant association between intelligence and the propensity to have affairs among men is a function of the greater physical attractiveness and height of more intelligent men.

The Hypothesis is about individual preferences and values, what people desire and want in their heads; it’s not necessarily about what people do. If people have complete choice over their behavior, then they may be expected to do what they desire and want, but they do not always have such complete choice. And, when it comes to sex and mating, men have very little choice.