by Angela Saini
“Being a woman hunter is a matter of choice. To keep an individual from performing certain tasks due to biological reasons is unthinkable to the Agta,” she described. “Lactation may temporarily cause a decrease in a woman’s active participation in hunting, but it certainly does not preclude her involvement in this activity.”
The key to making this possible was cooperative breeding, she adds. Women would take nursing infants with them on the hunt and leave older children in the care of other family members back home. Or a woman might nurse her sister’s baby while she was out hunting. “Even young adults could do the babysitting or keep an eye on the smaller children, cousins or siblings, left behind at the camp. Cooperative breeding is, I think, a very important component,” she explains.
The more the couple explored, the more they found that the women and men of the Nanadukan Agta were able and expected to do the same jobs. “By and large, people did whatever they wanted to do,” says Bion Griffin. No sphere of work was exclusively male or female, except perhaps killing other people. Women would stay back when groups of men went out on warlike enemy raids. “Some men did all sorts of child care, cooking, and so on. Others didn’t bother much with, say, cooking. I think everybody did everything. The only thing I can recall, I don’t recall men ever weaving baskets. But then, no one weaves baskets much. Men built houses with the women, men attended babies, they gathered firewood, they cooked, they pounded rice when there was rice to pound.”
Even as their old way of life disappears, the Nanadukan Agta have shown that, beyond the biological fact that women give birth and lactate, culture can dictate almost every aspect of what women and men do. The way lives are divided when it comes to child care, cooking, getting food, hunting, and other work is a moveable feast. There’s no biological commandment that says women are natural homemakers and unnatural hunters or that hand-son fathers are breaking some eternal code of the sexes.
The dilemma they pose for evolutionary biologists, though, is why they are the exception rather than the rule. Why don’t women hunter-gatherers everywhere hunt? And why aren’t all human societies just as egalitarian?
We sometimes imagine sexual equality to be a modern invention, a product of our enlightened, liberal societies. In actual fact, anthropologists have long known that the way women are treated throughout the world wasn’t always like this.
Anthropologist Mark Dyble, based at University College London, has studied another Agta community in the Philippines, known as the Palanan Agta, and analyzed this data together with that from a more distant group of hunter-gatherers in the Congo, a subgroup of the BaYaka, known as the Mbendjele. His research reveals a connection between the social structure of hunter-gatherer communities and high levels of sexual equality. It’s evidence, he suggests, that equality was a feature of early human society before the advent of agriculture and farming.
Published in 2015 in the journal Science, Dyble’s work built up detailed genealogies of hundreds of adults in these two communities. “We know as much as they know about their family histories. We even know if someone is second cousin with someone,” he tells me. These genealogies reveal that people living together are generally unrelated to each other. Women don’t always live with or near their husbands’ families and the same is true of men and their wives’ families. Sometimes they will switch between families, and sometimes they won’t live with close family at all.
Given the choice, people usually prefer to live with their own relatives all the time, because of the support and protection they can give them. “It’s not that individuals don’t want to live with kin,” Dyble explains. “It’s just that if everyone tried to live with as many kin as possible, this places a constraint on how closely related communities can be.” And this in turn means that neither men nor women have greater control over whom they live with. There must be sexual equality in decision making. “It has this transformative effect on social organization,” he says.
If this arrangement was normal in our evolutionary history, Dyble believes it could explain some aspects of human development. “We have the ability to cooperate with unrelated individuals, which is different from what we see in primates, which are very wary of interacting with individuals they haven’t met before,” he says. This is crucial to complex society. If people couldn’t cooperate with people they weren’t related to, civilization as we know it simply couldn’t exist. A study by anthropologist Kim Hill and his colleagues, published in the journal PLOS ONE in 2014, confirms that hunter-gatherers do interact widely with others. Their own data from the Aché in eastern Paraguay and Hadza in Tanzania suggest a person’s social universe can include as many as a thousand people over a lifetime. A male chimpanzee, by contrast, will only ever interact with around twenty other males.
This all points to the possibility that the way the Palanan Agta used to live may have been usual in our past. Historical investigations have always failed to uncover good evidence for matriarchal societies, in which women hold the reins of power. But that doesn’t mean humans weren’t egalitarian.
“There’s a general consensus now that hunting-gathering societies, while not perfectly egalitarian, were less unequal, particularly with regard to gender equality,” agrees Melvin Konner, a professor of anthropology at Emory University in Atlanta, who has spent many years doing fieldwork with hunter-gatherers in Africa. The communities he has studied have very little specialization of roles, he explains. There are no merchants or priests or government. “Because of the scale of the group dynamics, it would be impossible for men to exclude women. . . . Men and women participated, if not equally, women contributed at least 30 to 40 percent of the time.”
If the women of the Nanadukan Agta persisted with hunting for so long while others abandoned it earlier, one reason might have been their environment. The tropical forests in Luzon have fewer large and dangerous animals than in other parts of the world, such as South America, says Bion Griffin. Michael Gurven and Kim Hill, who have catalogued the reasons women don’t hunt, suggest that women avoid hunting as the risk of death rises. This is important to a group’s overall survival, because losing a mother is far more dangerous for a child than losing a father. In some societies and environments, hunting isn’t just dangerous; it can also take women far away from their home base for days at a time. If the culture does not provide enough support for women in terms of child care or other work, a woman may simply be unable to put in as many hours as a man to perfect her skills, making her a less useful killer.
Bion Griffin tells me that much of the resistance to the idea of women hunters comes from evolutionary theorists who can’t accept that hunting and motherhood are compatible. But among the Agta, hunting didn’t seem to put children at greater risk, as far as he and Agnes Estioko-Griffin could tell. It only brought in more food for everyone in a community in which food would otherwise have been desperately scarce.
Anthropologist Rebecca Bliege Bird, who has studied women hunter-gatherers in Australia, agrees. “There’s no reason why women wouldn’t hunt where hunting is an economically productive and predictable thing to do,” she says. One example she gives is that of the Meriam, an indigenous Australian society living in the Torres Strait Islands. They are skilled seafarers. On the beach, men spend more time line fishing, in the hope of bringing home a large, prized catch, while women choose to go after resident reef and shellfish where the odds of success are higher. As a result, women’s fishing harvests are more consistent and sometimes even more productive than men’s. “In most circumstances, hunting of large animals is not a very productive thing to do. I would guess that the majority of subsistence for most hunter-gatherers in most environments is the small animals. And women are going to be the major procurers of small animals,” she says.
Another example from the same continent is the Martu, an aboriginal tribe in Western Australia for whom hunting is a sport. Outrunning animals is a skill perfected by women in particular. “When Martu women hunt, one of their favorite prey
are feral cats. It’s not a very productive activity, but it’s a chance for women to show off their skill acquisition. Women gain huge notoriety going after these cats,” Bliege Bird tells me. The hunting is done in scorching summer heat. “Women chase after these cats. They run to tire them out. It’s just tremendous the amount of effort that goes into it.”
Even among the Aché in eastern Paraguay—a community in which women don’t hunt—there is evidence that women are still able to hunt if they want to. Ana Magdalena Hurtado, an evolutionary anthropologist at Arizona State University, has documented how Aché women act as “eyes and ears” for male hunters. She and her colleagues once saw an Aché woman hunting while carrying an infant. They concluded, “Aché women are capable of hunting but avoid doing so most of the time.” Their focus, instead, must be on other work.
When it comes to family and working life, the biological rule seems to be that there were never any rules. While the realities of childbirth and lactation are fixed, culture and environment can dictate how women live just as much as their bodies do.
For those who have spent their careers on the outside looking in, documenting these rare human societies whose ways challenge our stereotypes, this can be personally life changing. At the end of our interview, Bion Griffin and Agnes Estioko-Griffin tell me that there’s no sexual division of labor in their own household, just like there was none among the Nanadukan Agta they studied for so many years. “And so, I’m off to cook dinner now!” Bion laughs before he hangs up the phone.
At home in London, I realize with disappointment, I’m the one cooking dinner that night.
CHAPTER 6
Choosy, Not Chaste
If the world were ours too, if we believed we could get away with it,. . .the force of female desire would be so great that society would truly have to reckon with what women want, in bed and in the world.
—Naomi Wolf, The Beauty Myth, 1990
You’re at university and a stranger of the opposite sex sidles up to you. “I’ve been noticing you around campus. I find you to be very attractive,” they say. Before you know it, the mysterious person is inviting you back to their room to sleep with them.
It may be the least creative way of picking someone up, but if it works on you, then research suggests you’re almost certainly a man. This scenario was part of a real experiment at Florida State University conducted in 1978 and designed by psychology professors Russell Clark and Elaine Hatfield to settle a classroom dispute over whether, compared to women, men are more open to casual sex. Their method was simple. They recruited a bunch of young volunteers from an experimental psychology class, none of them too bad looking but none wildly attractive either, to approach people across campus and repeat the same pickup line. This was followed by one of three requests: to go out on a date, to go to their apartment, or to go to bed with them.
The results were stark. Even though men and women were equally likely to go on a date with a stranger, none of the women would sleep with one. Three-quarters of the men, on the other hand, were willing to have sex with a woman they didn’t know. When the psychologists repeated the experiment in 1982, the results were almost the same. The women, they observed, were often appalled at being propositioned in this way. “What is wrong with you? Leave me alone,” one said. The men were a different story, even apologizing when they refused. “In fact they were less willing to accept an invitation to date than to have sexual relations!” Clark and Hatfield noted.
For years they struggled to get their paper published for fear on the part of publishers that it was too frivolous. When it finally came out in 1989 in the Journal of Psychology and Human Sexuality under the title “Gender Differences in Receptivity to Sexual Offers,” it became a classic. After all, it neatly confirmed what everyone thought they already knew about sex and the sexes. Men are naturally polygamous and just fighting nature when they become tied into long-term relationships. Women are monogamous and always looking for the perfect partner.
It comes down to the fact, some biologists say, that males and females want fundamentally different things. They’re stuck in an endless evolutionary tussle—one indiscriminately chasing any female to boost his odds of fathering the most children, and the other trying to escape unwanted male attention in the careful search for the best-quality father for her offspring. Charles Darwin himself had laid this observation in scientific stone back in 1871 in his famous work The Descent of Man, and Selection in Relation to Sex.
The idea was even experimentally tested in 1948 in another mating experiment. This one wasn’t on humans, though, but on a humble little fly that appears when fruit rots.
When it comes to reproduction, the easiest species to study are those that mate quickly and breed abundantly. Humans are not that species.
Angus John Bateman, a botanist and geneticist working at the John Innes Horticultural Institute in London in 1948, was wise enough to pick the common fruit fly, a creature that lives so hard and fast that it’s sexually mature within a few days of birth and can lay hundreds of eggs at a time. What makes the fruit fly a scientist’s best friend is that it has genetic mutations that make each one look slightly different from the next, depending on what it inherits, such as curlier wings or narrower eyes. By tracking these differences, Bateman could reliably pick out which fly belonged to which parents. From this, he knew which flies were mating successfully.
Like Hatfield and Clark’s experiment, Bateman’s was simple. He took three to five adult females and the same number of adult males, then watched to see how they performed in the mating game. A fifth of the male flies, he found, didn’t manage to produce any offspring, compared with only 4 percent of the females. The most successful male flies, though, produced nearly three times as many offspring as the most successful female fly. None of the females were short of offers, but the least successful males suffered routine rejection. It confirmed Darwin’s long-standing theory that males in species like these are more promiscuous and less discriminating, while females are pickier and more chaste.
“Darwin took it as a matter of general observation that males were eager to pair with any female, whereas the female, though passive, exerted choice,” wrote Bateman. The fruit fly species he studied “seems to be no exception to the rule.”
Darwin had reasoned that when one sex has to compete for mates, there’s greater pressure on it to evolve the features the other sex is looking for. It needs to be strong enough to beat off the competition, too. He called this evolutionary process “sexual selection.” And his observations suggested that males faced far more of this pressure than females. This would explain why the males of certain species, including our own, tend to be bigger and stronger than the females. It explains, too, such marvels of nature as the lion’s giant mane and the peacock’s flamboyant blue and green plumage. There don’t seem to be any reasons why lions need manes or peacocks need such cumbersome, fancy feathers except to attract the opposite sex.
“There is nearly always a combination of an undiscriminating eagerness in the males and a discriminating passivity in the females,” wrote Bateman. His fruit fly experiment reinforced Darwin’s theory that sexual selection acts more heavily on males than on females. Some male flies were studs, others were duds, but none of them for want of trying. The competition was intense enough that a few did far better than the rest. The female flies, meanwhile, seemed to be comfortable in the knowledge that they could choose the males they wanted. They seemed to be under little pressure at all. In fact, according to Bateman, a tiny number were even willing to forgo mating for the moment if, presumably, they didn’t see what they liked.
Bateman’s observations of fruit flies, extrapolated to other species including our own, would renew scientific interest in sexual selection theory. But not immediately. His paper lay beneath the radar for decades. He never wrote about sexual selection again. It wasn’t until twenty-four years later that his fruit fly experiment was finally popularized by a young researcher called Robert Trivers.<
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Trivers, age seventy-three, has had a colorful life for a biologist.
His website, which promotes his autobiography—appropriately titled Wild Life—says that he’s spent time behind bars, that he founded an armed group to protect gay men in Jamaica from violence, and that he once drove a getaway car for a founder of the Black Panthers, the black nationalist organization active in the sixties and seventies. He was also the biologist who once told a reporter that biologist Sarah Blaffer Hrdy should focus on being a mother rather than on her career.
Today Trivers lives on a rural estate he’s bought in Jamaica. When I interview him over the phone, he tells me that he and the workers there call it “Man Town,” because there are no women around. When I ask him where he works nowadays, he says that he’s in a dispute with his employer, Rutgers University in New Jersey, which means that soon he’ll be out of a job. Apparently, he had been forced to teach classes on subjects he didn’t know anything about.
However much of a roller coaster his life has been, Trivers is considered one of the most influential evolutionary biologists in the world, in particular for theories he developed early in his career. A paper he published in 1972 about Angus Bateman’s 1948 fruit fly experiment has been cited by researchers at least eleven thousand times. Titled “Parental Investment and Sexual Selection,” it has fundamentally shaped the way researchers today understand sexual selection.
Trivers was just a young researcher at Harvard University, studying mating pigeons outside his window, when one of his tutors suggested he look up Bateman’s work. And he remembers it with graphic clarity. He went to the museum to photocopy it, “with my testicles firmly pressed against the side of the Xerox machine,” he tells me, with a throaty laugh. As soon as he read it, “The scales fell from my eyes,” he says. It would mark a turning point in his career.