Grabbing Men by the Testicles: A Selection from Joseph Henrich’s The WEIRDest People in the World (2020)
“From among our closest evolutionary relatives—apes and monkeys—guess how many species both live in large groups like Homo sapiens and have only monogamous pair-bonding? That’s right, zero. No group-living primates have the noncultural equivalent of monogamous marriage. Based on the sex lives of our two closest relatives, chimpanzees and bonobos, the ancestor we share with these apes was probably highly promiscuous and likely didn’t form pair-bonds at all, let alone enduring, monogamous pair-bonds. Nevertheless, since we diverged from our ape cousins, our species has evolved a specialized psychological suite—our pair-bonding psychology—that can foster strong emotional bonds between mates that remain stable for long enough to encourage men to invest in their mate’s children. This pair-bonding psychology provides the innate anchor for marital institutions. . . .
Polygynous marriage remains legal in much of Africa, Central Asia, and the Middle East. At the same time, nearly all modern legal prohibitions on polygynous marriage derive from WEIRD foundations, ultimately rooted in Christian doctrines. In Japan and China, the adoption of ‘modern’ (Western) marriage began in the 1880s and 1950s, respectively. In both cases, new governments explicitly copied Western secular institutions and laws, including prohibitions on polygynous marriage. In the 1920s, the new Republic of Turkey copied a whole set of WEIRD formal institutions and new laws, including prohibitions on polygynous marriage. In India, the Hindu Marriage Act of 1955 prohibited polygynous marriage for everyone except Muslims, who were still permitted to have up to four wives in accordance with their religious tradition. Naturally, this led some prestigious Hindu men to convert to Islam, thinking they’d found a legal loophole. In 2015, however, the Indian Supreme Court ruled that the law applies to everyone, no exceptions. Thus WEIRD monogamy is a relatively new import in most of the world. . . .
To understand testosterone (T), it’s best to step back, start with birds, and then shift to Homo sapiens. In birds, testosterone contributes to the development of secondary sex characteristics; but instead of the deep voices, hairy chests, and square jaws seen in humans, male birds variously develop brightly colored plumage, large combs, and fancy wattles. Across species, testosterone is also related to mating and courtship displays, including beautiful serenades and athletic dances, as well as to both territorial defense and male-male fights over females. These effects of testosterone appear in many mammals as well, but the cool thing about birds is that many species form enduring pair-bonds with only one other partner per season (‘monogamy’), and males even help out in the nest with the offspring—that is, they do paternal investment like fathers in many human societies. Of course, as is the case for 90 percent of mammal species, there are also many bird species that lack both pair-bonding and any male investment in nests, eggs, or chicks. This avian variation allows us to compare the effects of testosterone in species with different patterns of pair-bonding and mating. Do you see where I’m going? . . .
When song sparrows are fitted with special implants that prevent the normal testosterone drop that occurs after a male’s mate gets pregnant, males continue fighting and end up doubling the size of their territory relative to those sparrows lacking the implants. The males with implants also became polygynous, securing two or even three mates. In other bird species, testosterone implants increase both male singing and territorial aggression while reducing the birds’ efforts to feed their chicks or defend the nest. One suspects they were too busy singing and fighting to worry much about babies. Sound familiar?
In societies with WEIRD monogamy, men are a bit like monogamous birds: getting married and becoming a father lowers a man’s testosterone. If he divorces, his T levels typically climb again. . . . Across human societies, fathers with lower testosterone care more for their infants and are better attuned to their cries. WEIRD monogamy norms manipulate these dials by reducing the mating opportunities available to married men and by bringing them into greater contact with their children, both of which lower their testosterone levels. . . .
WEIRD marriage, which of course was built out of Christian marriage, generates a peculiar endocrinology. It’s widely believed by physicians that testosterone ‘naturally’ declines as men age. In the 21st-century United States, these drops are so severe that some middle-aged men are treated medically for low-T. But, as I’ve explained, across societies possessing more human-typical marriage institutions we don’t see these declines as often, and when we do, they aren’t nearly as steep as in WEIRD societies. It seems that a WEIRD endocrinology accompanies our WEIRD psychology. . . . the Church, through the institution of monogamous marriage, reached down and grabbed men by the testicles.”—Joseph Henrich, The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous (2020)
