“Through its ability to solicit and secure the attentive care not just of its mother but of many others in its sensory purview, a baby promotes many of the behaviors and emotions that we prize in ourselves and that often distinguish us from other animals, including a willingness to share, to cooperate with strangers, to relax one’s guard, uncurl one’s lip and widen one’s pronoun circle beyond the stifling confines of me, myself and mine.”
It is generally accepted that raising kids in a nuclear family of two adults is a post-WWII, US and Western Europe-centric habit. Throughout most of human existence on this planet, and even today in many cultures outside US and Western Europe, infants are reared by more than two people. Joint families that include living with at least the parents on the father’s side is very common in India, for example. In many cultures including India, the older siblings share the responsibility of raising a younger sibling, especially after the infant has been weaned. My father, the eldest son, told me how as a child, he had to rock the cradle while his younger sister slept. He said, “If she was awake, I was off the hook. I’d get so bored sometimes rocking the cradle, I’d pinch the baby and wake her up.”
Allomothers is the technical term used for like-a-mother caregivers of an infant. Cooperative breeding is another term used to describe the same principle. It is a reproductive strategy that has the potential to allow the females to reduce the time between offspring by reducing the burden that she alone has to carry. In apes such as chimpanzees and gorillas, primatologists observed that the mother was left to raise her offspring on her own. Another male or female is likely to kill another’s infant to increase the chances of survival of their offspring. A mother therefore guards the baby and refuses it to be carried or handed over to another member of the group.
For a behavior to be selected, there must be an advantage to all parties involved. The benefit to the mother in allomothering is clear, but what is the benefit to the allomother ? If it is the father, the benefit is again clear, his offspring survive. But if the allomother is not related, what is the benefit ? The currently accepted hypothesis is that caring for other’s infants makes a female a better mother and therefore increases the chances of survival of her offspring. If this hypothesis were true, then inexperienced females should tend to provide allomothering compared to experienced females and the offspring of allomothers should have a higher survival rate than those of non-allomothers. Sarah Hrdy’s study of Hanuman Langur monkeys at Mount Abu in India provided support for this hypothesis. She found that females who had not been mothers yet were willing to be allomothers more often than females who already were mothers. Lynn Fairbanks found that in vervet monkeys, females with high alloparenting experience had a 100% success rate in raising their offspring to maturity while the inexperienced females had only a 50% success rate.
Multiple points of data support the idea that humans evolved to be cooperative breeders. A recent article in ScienceDaily quoted a study by an anthropologist, Barbara Piperata, which stated that because of social support during the breast-feeding phase (upto about 18 months), mothers are able to conserve their energy and become fertile more rapidly compared to other apes which lack such a social support. Another theory that I came across in Meredith Small’s “Kids:How Biology and Culture Shape The Way We Raise Our Children” is based on the observation that humans are unique among the great apes in having a childhood, a stage where an infant has been weaned but is still dependent on adults for feeding and protection. Other apes go from infancy to juvenile phase without passing through a childhood phase. The reason we evolved to have a childhood, according to this theory (by Dr. Barry Bogin), is because older siblings can be alloparents, reducing the burden on mothers and freeing them to reproduce sooner. These two theories state that these are the reasons why humans can reproduce every 2 or 3 years, double or triple the rate of our other great ape cousins, the gorilla and the chimp, which reproduce only every six or seven years.
When I explained all this to Shanthala, she told me about the evolutionary reason for menopause. It’s called the “Grandmother Hypothesis”. Women have menopause because this allows them to be allomothers, help raise their grandchildren instead of continuing to invest in their own offspring. Dr. Hrdy argues that recent research has overturned the idea that humans are a patrilocal society i.e. women join the husband’s family. When it comes to raising an infant, women frequently return to their birth homes, using the experience and help provided by her mother. This custom is true in Indian culture. My mother (and I suspect that’s true for most of my generation) came away to her parent’s place when she was in the final stages of her pregnancy. My father was not even there when I was born and it would be six more months before my mother and I returned to join my father. This tradition continues with a slight twist for all of us immigrant families. Since most immigrants to this country consider it advantageous to give birth here than back in their home country, the women’s parents come to stay with them for an extended period during this time. In many cases, it is the only time the wife’s parents ever come to this country to visit their daughter.
All this is old hat, in some sense. What the NYT article talks about is Dr. Hrdy’s hypothesis that many facets of human behavior are better explained because we’re cooperative breeders than by the fact that we have complex brains. For example, to allow others to raise your infant, you must be willing to trust them; both must evolve a theory of mind i.e. be able to place themselves in the other’s shoes and empathize with them, be able to understand what they might think and feel in a given situation and respond appropriately. She argues that we developed our complex emotional behavior long before we evolved larger brains. She offers evidence of cooperative breeding in other animals such as lions and meerkats that you don’t need large brains to evolve cooperative breeding.
According to the NYT article, Dr. Hrdy has her bias in putting forth this new theory. From the article:
“Dr. Hrdy wrote her book in part to counter what she sees as the reigning dogma among evolutionary scholars that humans evolved their extreme sociality and cooperative behavior to better compete with other humans. “I’m not comfortable accepting this idea that the origins of hypersociality can be found in warfare, or that in-group amity arose in the interest of out-group enmity,” she said in a telephone interview. Sure, humans have been notably violent and militaristic for the last 12,000 or so years, she said, when hunter-gatherers started settling down and defending territories, and populations started getting seriously dense. But before then? There weren’t enough people around to wage wars. By the latest estimates, the average population size during the hundreds of thousands of years of human evolution that preceded the Neolithic Age may have been around 2,000 breeding adults. “What would humans have been fighting over?” Dr. Hrdy said. “They were too busy trying to keep themselves and their children alive.”
Having returned from a five week visit to India, I’m now alone again in caring for Maya the days that Shanthala is at work. In India, the task was made somewhat simpler because of all the help that we had in caring for Maya from our parents and friends to household help. All this talk of cooperative breeding makes me rather envious, and a little sad.
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Oh yes,will you kindly place yourself in Maya’s place and remember how you grow up,you were a prince as a baby for me and your Mother,be happy sad not sad sad.