Inferior

by Angela Saini

  Primates are different. According to Sarah Hrdy, there are nearly three hundred primate species, and in about half of them you’ll rarely see a female ape or monkey out of contact with her child. The infants, in turn, stick close to their mothers, sometimes for years. “Under natural conditions, an orangutan, chimpanzee, or gorilla baby nurses for four to seven years and at the outset is inseparable from his mother, remaining in intimate front-to-front contact a hundred percent of the day and night. The earliest a wild chimpanzee mother has ever been observed to voluntarily let a baby out her grasp is three and a half months,” Hrdy notes in her 2009 book, Mothers and Others: The Evolutionary Origins of Mutual Understanding. She includes a picture she once took of a female langur who was so attached to her baby that she faithfully carried around its corpse after it died.

  Others have made similar observations. “Mothers carrying dead infants is not uncommon in the primate world,” confirms Dawn Starin, a London-based anthropologist who has spent decades studying primates in Africa, Asia, and South America. In her research on red colobus monkeys in Gambia, one female “carried her maggot-riddled infant around with her for days, grooming it, sticking it in the crotches of trees so that she could feed without it slipping to the ground, and never letting any of the others touch it.” Encounters like these left her with the impression that an infant is treated like an extension of the mother’s body, a real part of her, and not a separate being.

  For humans, the universal pattern seems to be that mothers are just as protective of their children but not so constantly attached. This isn’t something that’s true only of modern parents in big cities but everywhere across the world. It really does take a village to raise a child.

  For anthropologists trying to get a grip on our evolutionary history, the best case studies are people who live the way our earliest ancestors might have, hunter-gatherers. Modern-day hunter-gatherers are rare and dwindling, drawing a subsistence living off the land, foraging for wild plants and honey, or hunting animals. They’re an imperfect window on our past, partly because each community is different from the next, depending on its environment, and also because other cultures have encroached on them over the years and distorted how they live. But by watching their lifestyles and behavior, we can still get some sense of how humans might have lived many thousands of years ago, before societies began domesticating animals and before agriculture.

  Some of the most studied hunter-gatherer groups are in Africa, the continent from where all humans originally migrated. This makes them arguably the most reliable source of data for evolutionary researchers. They include the !Kung, bushmen and bushwomen living in the Kalahari desert in southern Africa, the Hadza who live in the Lake Eyasi region of northern Tanzania, and the Efé in the Ituri Rainforest in the Democratic Republic of the Congo. Anthropologist Sarah Hrdy notes that all three of these societies have people who play parental roles to other people’s children—known as “alloparents.”

  She describes this system as “cooperative breeding.” In her book Mothers and Others she writes, “!Kung infants were held by others some twenty-five percent of the time—a big difference from other apes, among whom new infants are never held by anyone other than their mother.” Among the Hadza, newborns are held by alloparents 31 percent of the time in the first days after birth. For children under four years of age, people other than their mothers hold them around 30 percent of the time. In central-African foraging nomadic communities, including the Efé, mothers share their babies with the group immediately after birth, and they continue this way. Efé babies average fourteen different caretakers in the first days of life, she adds, including their fathers.

  One more difference between humans and apes is how we give birth. Chimpanzee females are known to move away and seek seclusion before they give birth, to hide from predators or others who might harm their newborns (chimps enjoy meat, and have been known to kill and eat infants of their own species). Humans, on the other hand, do exactly the opposite. Expectant mothers almost always have people to help them when their babies are due. In my case, it was an entire team, including my husband, sister, doctors, and a midwife. Anthropologists Wenda Trevathan at New Mexico State University and Karen Rosenberg at the University of Delaware have noted that childbirth is a lonely activity in few human cultures. Helpers are so important that women may even have evolved to expect them, they’ve argued. Their theory is that the awkward style of delivery of human births and the emotional need that mothers have to seek support during birth may be adaptations to the fact that our ancestors had people aiding them when they delivered their babies.

  All this evidence suggests that cooperative breeding is an old and universal feature of human life, not a recent invention. And there are good reasons why. “One of the primary traits that we have is that we’re sort of the rabbits of the great ape world,” explains Richard Gutierrez Bribiescas, professor of anthropology at Yale University, who has studied the role of fathers in human evolution. “We have very high fertility compared to other great apes, compared to chimpanzees, gorillas, and orangutans. And we tend to produce these very large offspring that require a lot of long-term care,” he tells me.

  Most primates, meanwhile, will generally wait until the first infant has matured before having the next. A female bonobo would struggle to feed herself and move lithely through the forest if she had to drag around a litter of baby bonobos clinging to her fur.

  Two notable exceptions are titis and tamarins, both species of New World monkey in which fathers are extraordinarily involved in child care. Anthropologist Dawn Starin tells me, “When I studied a group of titi monkeys in Peru, the infant was usually carried by the father and spent most of its time with him. The father is completely involved with the rearing of the young. The mother was really just a dairy bar, a pair of milk-secreting nipples.” Like humans, titi monkeys are cooperative breeders. Some captive studies on this species, she says, have even suggested that the infant may be primarily attached to the father rather than the mother.

  Tamarin monkeys also rely on the efforts of both parents, simply to cope. “With tamarin monkeys, for reasons we don’t understand, they twin, and the twins are very large,” explains Bribiescas. “So the only way that can be viable is. . .some kind of paternal care. Otherwise it is very unlikely that the mother would be able to support these two very large twins.” This support is so vital that tamarins are known to neglect their children if they don’t have the help anymore. Sarah Hrdy has noted, according to data from a colony living at the New England Primate Research Center, that when a tamarin mate dies, the infants’ survival odds plummet. “There was a twelve percent chance of maternal abandonment if the mother had older offspring to help her, but a fifty-seven percent chance if no help was available,” she writes.

  Abandonment and neglect like this are rare. In the thousands of hours that scientists have watched monkeys and apes in the wild, very rarely has anyone seen one injure her infant deliberately. Primate mothers may be incompetent sometimes, especially with their first babies, but they hardly ever choose to let their offspring die. This, too—shocking though it may sound—is a feature in which humans again mark themselves out from their evolutionary cousins.

  The maternal instinct in humans is not an automatic switch, which is flicked on the moment a baby is born.

  This is Sarah Hrdy’s radical proposition. All over the world, mothers are known to admit that it takes time for them to fall in love with their babies, while some never do. In some unfortunate cases, mothers deliberately neglect and even kill their newborns. This may seem utterly unnatural. After all, we assume the maternal instinct is as strong and immediate in humans as it is in any other creature. It’s considered a fundamental part of being a woman. So much so that those who don’t want children or reject their own are sometimes considered odd. But the reality, observes Hrdy, is that it’s more common for mothers not to form an immediate attachment to their offspring than we like to believe.

  Her argu
ment is that this is a legacy of cooperative breeding. Like tamarin monkeys, humans often rely on help to cope with raising their children. Hormones released in pregnancy and childbirth help a mother bond to her baby. But this bond may also be affected by her circumstances. If her situation is particularly dire, she may feel she has no choice but to give up altogether.

  In Britain, studies estimate that between thirty and forty-five babies are killed every year—about a quarter of these within the child’s first day of life. According to research in 2004 by Michael Craig, a lecturer in reproductive and developmental psychiatry at the Institute of Psychiatry at King’s College London, this is likely to be an underestimate, because these kinds of killings can easily go unreported. But even as the reported figures stand, infants are at a bigger risk of homicide than any other age group. For the babies killed soon after birth, the most common perpetrators are teenage mothers, especially those who are single and living at home with parents who might be disapproving of their pregnancies. Most of them aren’t killing their babies because they’re psychotic or mentally ill, says Craig, but because of the desperate positions they find themselves in.

  To make her case, Sarah Hrdy has also investigated a particularly grisly historical example. In the eighteenth century in urban parts of France, as many as 95 percent of mothers sent their children away to be wet-nursed by strangers, sometimes in questionable conditions. Her research, outlined in a series of lectures she gave at the University of Utah in 2001, suggests that the mothers must have known this would dramatically lower their babies’ odds of survival. Culture dictated that they do it, so they did. The deadly practice was evidence, she argues, that not every human mother protects her newborn at all costs. Female infanticide in Asia today is sometimes also carried out with the complicity of mothers. Again, society influences how they respond to a birth.

  Hrdy’s hypothesis about the profound importance of cooperative breeding is a difficult one to prove, especially given the myriad pressures that pregnant women experience in the modern world. But it also has the power to release women of the guilt they may feel when they’re unable to cope alone. If we are natural cooperative breeders—a species in which alloparents are part of the fabric of families—it’s unreasonable to expect women to manage without any help. For Hrdy, a feminist, this line of research also has obvious political implications. It reinforces why lawmakers shouldn’t outlaw abortion and force women to have babies they feel they cannot raise or do not want. It also highlights how important it is that governments provide better welfare and child care for mothers, especially those who don’t have support at home.

  The weight of evidence does at least seem to be in favor of the idea that humans didn’t evolve to raise their children single-handedly. Child care was not the sole responsibility of mothers. “What we’re finding is that cooperative breeding in humans is becoming more and more important in terms of our thinking,” agrees anthropologist Richard Bribiescas. As evidence builds around this and what it means, it’s becoming clearer just how important alloparents are in the human story. And it also raises an interesting question: If mothers didn’t evolve to parent alone, who else around them would have been providing the most support?

  “We see a huge range of plasticity in how much engagement there is in human males.”

  Sarah Hrdy tells me that when she welcomed her first grandchild last year, she took the opportunity to run a small experiment on her family. Arriving at her daughter’s house, she took saliva samples from herself and her husband. She took another set of samples after spending time with the new baby. Tests revealed that they had both experienced a rise in oxytocin, the hormone associated with love and maternal attachment.

  Our bodies betray how strong the emotional connections can be between children and people who aren’t their parents. Physical contact with a baby, scientists have long known, can have dramatic effects on a mother’s hormone levels. These hormones in turn influence how she bonds with her child. Others who aren’t mothers, we now know, can experience these hormonal changes, too.

  Evolutionary biologists have often assumed in the past that, of all the people providing support to mothers, fathers would have been front and center. In his 2006 book, Men: Evolutionary and Life History, Richard Bribiescas suggests exactly this. And from the perspective of how we’ve lived for centuries, often in monogamous marriages and nuclear families, this seems to make sense. Even if they weren’t directly involved in child care, the material help that fathers brought to families, such as food, must have been crucial to keeping children alive and thriving.

  Some recent studies, however, don’t agree. In a 2011 paper in Population and Development Review, Rebecca Sear at the London School of Hygiene and Tropical Medicine and David Coall at Edith Cowan University in Australia pulled together all the published studies they could find on how the presence of fathers, grandparents, and siblings affect a child’s survival. They found that other family members were so valuable that, once a child passed the age of two, they could even cushion the impact of an absent mother. Where this help came from, though, was more of a surprise. Older siblings had a more positive effect than anyone besides the mother. After this came grandmothers, then fathers, followed far behind them all by grandfathers.

  “Fathers were rather less important: in just over a third of all cases did they improve child survival,” Sear and Coall note in their paper.

  This doesn’t mean that hands-on fathering isn’t important. Just that it isn’t always there. In 2009 anthropologist Martin Muller at the University of New Mexico and his colleagues studied how much effort men in two neighboring but different East African communities put into parenting. In one, the Hadza hunter-gatherers, they found that fathers were involved in everything from cleaning to feeding infants, spending more than a fifth of their time interacting with children under three if they were in the camp at the same time, and also sleeping close to them. In the other, a pastoralist and warrior society called the Datoga, they found a strong cultural belief that looking after children was women’s work, with men eating and sleeping separately and not interacting much with infants. Their hormone levels reflected the difference in parenting styles. The more involved fathers—the Hadza—produced less testosterone than Datoga fathers.

  “We see a huge range of plasticity in how much engagement there is in human males,” admits Richard Bribiescas, from “the most doting and caring father, and everything is great and lovely, to a father that’s sort of engaged and maybe just brings food and resources home, to the ultimate, very horrific cases of things like infanticide.” If society expects men to be involved in child care, they are, and they can do it well. If society expects them to be hands-off, they can do that, too.

  This plasticity is unique to humans. “In other great apes and other primates you simply don’t see that. They’re locked into one strategy,” he adds.

  If in our evolutionary history, caring for children is something that would have been done not just by mothers but also by fathers, siblings, grandmothers, and others, the traditional portrait we have of family life starts to crack. A nuclear family with one hands-on father certainly isn’t the norm everywhere. In a few societies, for example, children even have more than one “father.” In Amazonian South America, there are communities that accept affairs outside marriage and hold a belief that when a woman has sex with more than one man in the run-up to her pregnancy, all their sperm help build the fetus. This is known by academics as “partible paternity.” Anthropologists Robert Walker and Mark Flinn at the University of Missouri and Kim Hill at Arizona State University, who have confirmed how common partible paternity is in the region, claim that children benefit from these family arrangements. With more fathers, their odds of survival go up. They have more resources and better protection from violence.

  This all points to the possibility that living arrangements among early humans could have taken any number of permutations. Monogamy may not have been the rule. Women, if they weren’t tied
to their children all the time, would have been free to go out to get food and perhaps even hunt. The Victorian ideal that Charles Darwin based his understanding of women upon—mother at home, taking care of the children, hungrily waiting for father to bring home the bacon—is left out in the cold.

  “A theory that leaves out half of the human species is unbalanced.”

  It was April 1966.

  Some of the most important names in anthropology had come together at the University of Chicago to debate what was then a fast-growing body of research about the world’s hunter-gatherers. The symposium they were all a part of was headlined “Man the Hunter.” And they would help shape the way a generation of scientists thought about human evolution.

  The gathering was appropriately titled. The “man” in the title, as anyone attending would have guessed, really did refer to men, not to all humans. In almost no hunter-gatherer communities were women known to routinely hunt. Even so, this one activity was believed to be the most important in human evolutionary history. Hunting made men band together in groups and work cooperatively, so they could target their prey more effectively. It forced men to be inventive and create stone tools. Hunting may also have been what prompted men to develop language so they could communicate more effectively. By bringing home meat, followed the logic, men were able to provide themselves, women, and their hungry children with the densely packed nourishment they needed to develop bigger brains and become the smart species we are today.

  Hunting was everything.

  “In a very real sense our intellect, interests, emotions and basic social life—all are evolutionary products of the success of the hunting adaptation,” wrote leading anthropologists Sherwood Washburn and Chet Lancaster in their chapter of a 1968 book about the symposium, also titled Man the Hunter. The importance of the kill, dramatic as it was, would later be popularized for a wider audience in a 1976 book by Robert Ardrey, a Hollywood screenwriter who changed career to focus on anthropology. “It is because we were hunters, because we killed for a living, because we matched wits against the whole of the animal world, that we have the wit to survive even in a world of our own creation,” he wrote in The Hunting Hypothesis.