Sex, Power, and Partisanship: How Evolutionary Science Makes Sense of Our Political Divide - Hector A. Garcia 2019

The Defensive Game of Male Mate Competition
The Politics of Sexual Control

There is a group of birds from the family Cuculidae that engage in a notorious evolutionary reproductive strategy called brood parasitism. Three New World and fifty-six Old World species of bird engage in this strategy, which involves laying their eggs in other birds’ nests—often birds from different species. By doing so, the cuckoo birds, as they are commonly known, offset all the energy expenditure and risk associated with rearing offspring onto another animal. Worse yet, the cuckoo nestling kills its forced adoptees’ offspring by ejecting their eggs. Unaware of the switch, the host species instinctively feeds the cuckoo chick into adulthood. Sometimes the costs incurred by the cuckolded birds, which are often much smaller species, are painfully clear, with an outsized cuckoo chick greedily demanding food from tiny stepparents who practically kill themselves trying to keep up with the voracious imposter's caloric needs. Critically, this herculean feeding effort is done to support a chick with foreign DNA, which makes it not only evolutionarily profitless but also dangerous; in an uncertain natural world filled with hazards, spending an entire breeding season on an imposter chick could mean complete failure to reproduce, an evolutionary dead end.

The risks of cuckoldry are not limited to birds, however, and in fact turn out to form the basis for an enormous share of male human reproductive psychology. Despite the fact that men tend to seek casual sex, they also take risks and invest time and resources in caring for their offspring. Because provisioning human offspring can take decades, the concern over being cuckolded is an important adaptation that prevented our male ancestors from being duped into nurturing foreign DNA. Even today, a large body of evidence shows that, when compared with women, men worldwide are more jealous of sexual infidelity, which places them at risk of cuckoldry.¹ Women, on the other hand, tend to be more jealous of emotional intimacy, which might lead to resources being diverted to another woman's children.² This is not to say that women don't get sexually jealous (or that they shouldn't). But a woman always knows whether a child is hers, which makes sexual jealousy (relatively) less critical for her reproductive success.

Cuckoldry, moreover, is a concern shared with other nonhuman male primates, including chimpanzees, baboons, and gorillas, all of whom use a variety of strategies to prevent it. They may attack potential rivals or straying females. Male monkeys and apes have been seen chasing, biting, and dragging females as punishment for flirting with or grooming other males, or simply being within a rival male's vicinity. They may also engage in mate guarding, constantly monitoring the female during her fertility phase to ensure sexual primacy.³

Men too engage in these ancient behaviors. Unlike ovulation in most other primates that show obvious sexual swellings, ovulation in women is hidden. Yet research has found that men have the unconscious ability to smell fertility. In one study, researchers had women wear cotton underarm pads at different phases of their menstrual cycle. When the researchers asked men to rate the smell of those pads on “pleasantness” and “sexiness,” men consistently rated pads worn during the follicular phase (when the egg is ready for fertilization) higher on sexiness.⁴ Compelled by this primitive sense, men are inclined to mate guard. One study found that men engaged in more mate guarding during their mate's follicular phase—calling their partners unexpectedly, monopolizing their time, or displaying anger when they talk to other men.⁵ As among nonhuman male primates, mate guarding can become aggressive, and men may attack their mates in an effort to dissuade partner defection. Research finds that sexual jealousy is a primary motivation for spousal violence, including spousal homicide, both of which are almost always perpetrated by men.⁶

Once again, because men usually run human societies, male reproductive strategies have a way of working themselves into the political arena, where they are often concretized into law. In Texas, for example, it was legal to murder your wife if you caught her cheating as late as 1974.⁷ In Italy, men committing this kind of murder were given special light prison terms (three to seven years) until 1981.⁸ In Uruguay, a conservative penal code allowed judges to completely pardon men who committed murder as a result of “passion provoked by adultery” until 2017.⁹ There are other examples, but the key message here is that conservative laws enforcing female sexual control are greatly driven by male cuckoldry concerns.

For a deeper understanding of how the ancient, animalistic fear of cuckoldry forms a major pillar of present-day statecraft, we turn our attention to the nations where political conservatism tends to be most concentrated. If our hypothesis about conservative politics as a male reproductive strategy is correct, female sexual control should also be at its peak in those nations.