The New York Times, April 5, 2022


This year marks the 40th anniversary of “Chimpanzee Politics,” a book that forced us to look at our simian cousins in a new light. The author, a Dutch primatologist named Frans de Waal, offered an unprecedented look at the social world of chimpanzees. Their lives are crammed with alliances, betrayals, and Machiavellian maneuvers. “Chimpanzee Politics” was also the debut of a gifted writer. De Waal turned what might have been a dry monograph into something that read more like a character-packed novel.

De Waal has been busy in the four decades since. He has studied other primates, such as bonobos, a species that split from the chimpanzee lineage about two million years ago. Unlike chimpanzee societies, in which males typically dominate, bonobo societies turn out to be run by the females.

De Waal has also found the time to write a string of books that have attracted readers far beyond primatology circles. In his recent works, such as “Mama’s Last Hug” and “Our Inner Ape,” de Waal has extended his gaze to humans, and argued that we may not be as special as we think. Apes have their own kind of politics. They have emotions and morality too.

In “Different,” de Waal turns his attention to gender. “Whereas it is true that gender goes beyond biology, it’s not created out of thin air,” de Waal writes. “There is every reason,” he writes elsewhere, “to see what we can learn about ourselves from comparisons with other primates.”

De Waal starts with boys and girls. He rejects the idea that they play differently merely because of how they’re raised. He observes that young chimpanzees exhibit similar differences: The males tend to roughhouse, while females often pretend to carry infants.

For young primates, playing serves as training for adult life. Adult males tend to rely on muscle to dominate other males in their hierarchy. Adult females are largely responsible for caring for young. While these differences matter, de Waal says, they shouldn’t be used to defend simplistic notions about how men and women ought to behave.

Take the term “alpha male,” which de Waal himself helped to popularize. Much to his chagrin, some business writers came to use the term for a man who bullied his way into the corner office, crushing rivals along the way. “They forget to mention the skills that set a good chimpanzee alpha male apart, such as generosity and impartiality,” de Waal writes.

De Waal also points out that the roles of male and female primates have fuzzy, overlapping boundaries, not sharp borders. “Over decades of working with apes, I have known quite a few whose behavior was hard to classify as either masculine or feminine,” he writes. He’s seen muscle-bound males retreat from confrontations. He spent many hours observing a female chimpanzee named Donna who would raise her hairy coat like a male chimpanzee and showed no interest in mating with males. “The best way to describe her is perhaps as a largely asexual gender-nonconforming individual,” de Waal writes.

It might sound odd to hear the word “gender” used to describe a chimp, even if it’s a gender-nonconforming one. Sex is a matter of the chromosomes, hormones, eggs, and sperm. Gender has to do with the roles that the sexes play in a society — roles molded by culture.

Primates have cultures of their own. One group of chimpanzees may smash open nuts with rocks, while a nearby group uses sticks to fish for termites. Once primates invent a custom, it gets passed down through the generations as young primates learn it.

De Waal speculates that young male and female primates develop their gender roles in a similar fashion. They look to adults to learn how to behave. Young males are biased to learning from older males, he argues, while the young females look to their older counterparts.

If de Waal is right, then the behavior of males and female primates aren’t as hard-wired as we might think. Under certain conditions, they have the potential to start doing things we might expect from the opposite sex. De Waal observes how male rhesus monkeys never take care of infants — unless they’re alone with one without any adult females around.

The primate tales that de Waal uses to discuss gender are both fascinating and enlightening. He remembers rhesus monkeys he studied in the 1980s much more clearly than I remember a lot of the people I went to college with. But as an argument about humans, I found “Different” less satisfying.

De Waal sometimes stretches evidence to fit his claims. He argues that girls dress up in princess outfits because it feels good to conform to our own gender. For evidence he cites a single brain-scanning study of just 19 subjects.

“Imitating people of one’s own gender activates reward centers in the brain, whereas imitating people of the opposite gender does not,” de Waal claims. But the study itself showed that imitating the opposite gender did activate those reward centers. It’s just that the scientists saw a stronger response for the same gender.

The authors of the study did not claim, as de Waal does, that it’s evidence of an innate “feel-good bias” that locks in genders. They instead raised the possibility that boys and girls simply learn to act the way they’re encouraged to act by parents, teachers and other children.

When De Waal asserts that male apes and men are both judged by the width of their shoulders, he doesn’t even offer a footnote. After observing that male chimpanzees exaggerate their size by making their hairs stand up, he turns to men’s fashions. “We too pay special attention to male shoulder width, which is why suits have shoulder pads,” de Waal declares.

Professor de Waal, I have Joan Crawford on line one waiting to talk to you. Joan Collins is on line two.

Sometimes de Waal’s evidence for a link between humans and other primates feels more like free association. When discussing violence inflicted by men on women, he claims that unrelated women can protect each other just as female bonobos do. “The #MeToo movement comes to mind. So does the Green Sari movement,” he writes.

“Different” would have benefited from less free association and more sustained argumentation. I was not sure what to make of the fact that humans are like chimpanzees in some regards and bonobos in others. After all, they’re both equally related to us, belonging to a lineage that split off from our own around six million years ago.

When de Waal ventures further away on the primate tree, things get more confusing. In a chapter on parental care, he describes how cotton-top tamarin fathers put in a lot of effort raising young. (They can burn off 10 percent of their body weight lugging around their kids.) As we’re waiting to learn what cotton-top tamarin fathers can tell us about human fathers, de Waal loses interest. “These monkeys are quite distant from us, however, which makes them less relevant to human evolution,” he declares, turning to gibbons. Will cotton-top tamarins be on the midterm?

There’s a deeper problem with writing about cotton-top tamarins this way: They are different from their own close relatives. The ancestors of cotton-top tamarins started out as a species in which fathers offered little care at all. And then a mysterious combination of evolutionary factors pushed the ancestors of cotton-top tamarins onto a peculiar path.

We humans are peculiar too. We may not be quite as special as we’d like to think, but we have undergone some big changes since our lineage split from chimpanzees and bonobos. Our ancestors started walking upright, lost much of their hair, evolved big brains, and began speaking full-blown language. It is hard to tell from “Different” to what degree our genders have been shaped by history before and after our split from our fellow primates.

None of this is to take away the value of the stories of Donna and the rest of the primates that have filled de Waal’s life. If you don’t know your bonobo from your gibbon, “Different” has many surprises in store for you, surprises that will leave you humble about complex primate evolution has been, and how much we have yet to learn about how it shapes our lives.

Copyright 2022 The New York Times Company. Reprinted with permission.