Image: John Watson

Frans de Waal: ‘Female monkeys pick up the dolls and males pick up the trucks’

The primatologist on what apes can teach us about sex and gender
July 21, 2022

Could studying apes help us to solve the vexed questions about sex and gender in humans? If anyone has the answer it’s Frans de Waal, the 73-year-old Dutch primatologist who has made a lifetime’s study of our ape cousins. “There are two extreme positions,” he tells me on a visit to the Prospect offices. Some progressives say it doesn’t matter if you’re a man or a woman—“the only difference is what is between your legs”—while conservative politicians in the US “say there are men and women, and that’s how nature works.” But as de Waal argues in his book Different, there is no “simple answer.” 

There are some “core differences” he has observed: men, like all primates, are more violent, while women have more empathy. Give human toys to monkeys and “the females pick up the dolls and the males pick up the trucks.” A study of orangutans showed that young females ate exactly what the adult females did, whereas the young males had a more varied diet. He puts this down to “self-socialisation,” where a child copies the behaviour of the same gender.

De Waal describes #MeToo as a typical bonobo movement of female solidarity

I mention that my own toddler daughter likes trucks more than dolls. “There are exceptions, of course,” he says. 

Just as biology is important in humans, so is acculturation for apes. He cites Donna, an alpha female chimpanzee who from a young age liked to “wrestle” with males; she showed no interest in mating and from a distance was mistaken for the opposite sex. He doesn’t go quite so far as to call her a “trans ape”—he speculates that the cause of her behaviour could be hormonal—but he says Donna certainly seems to have a “gender identity” at odds with her ostensible biology. 

When de Waal started out, biologists were strongly influenced by ethologist Konrad Lorenz’s book On Aggression and its account of violent conflict between animals. Growing up in a household as one of seven brothers, de Waal says with a smile, “we had plenty of competition.” But when studying apes, he became more interested in looking at co-operation and empathy—“feminine” traits—which he puts down to his upbringing in a consensus-driven Dutch society.

He became fascinated with bonobos, a close relation of ours whose societies are much more female-centred than those of chimpanzees. “They have a very tight sisterhood, and they dominate the males and resolve a lot of their issues with sex.” (Recent DNA tests have shown that female apes in general take multiple male lovers—often sneaking off at night with a new partner as the alpha male sleeps.) He describes #MeToo as “a typical bonobo movement… of female solidarity.”

One apparently universal ape trait is that females look after the babies. But even here de Waal has observed counter-examples: when a baby chimp is orphaned, the females are often too busy with their own offspring to take care of them. So a single, high-ranking male may adopt one “for three or four years—be protective of them, sleep with them and make sure that they eat.” The fact that humans developed nuclear families, with men playing an important role in offspring care, has given us an evolutionary advantage: we can have babies at shorter intervals, thus increasing our population.

Still, de Waal is sceptical of attempts to pretend men and women are the same. “The chimpanzees I’ve worked with,” he says, “the males relate very easily—they don’t see me as competition because I’m outside the group.” With bonobos, “it matters to them that you’re female.” He mentions a female student of his who was watching the bonobos at San Diego zoo. In a welcoming gesture, the bonobos threw some food towards her, something they had never done with him. “They considered her part of the group.”