In Mothers and Others, Sarah Blaffer Hrdy joins the many scientists and theologians who have sought to determine what traits are unique to humans and why humans behave as they do. The serious involvement of science with these two questions dates back to the great British naturalist Charles Darwin and his book The Descent of Man and Selection in Relation to Sex (1871). Building on this massive work, later biologists and anthropologists have projected multiple, separate ideas of what makes people uniquely human and what distinguishes them from the other primates. Walking upright, the ability to make fire, the capacity to learn language, the mix of cooperation and competition needed for hunting big-game animalsall have been theorized as the crucial turning point that differentiated Homo sapiens’ ancestors from their great ape relatives and set them on the path to full humanity.
Sociobiology, now often called evolutionary psychology, attempts to explain human social behaviors in terms of the evolutionary mechanisms that produced them. From the beginning of her career, Hrdy has been one of a very few sociobiologists who viewed the activities of early protohuman females as being at least as significant for human evolution as were those of males. Two of her previous books have documented strategies used by primate females to maximize their own, and their descendants’, survival chances.
In Mothers and Others, Hrdy explores in great depth a key feature of her research and thought: the demands and social effects of human motherhood. She argues that the innate conditions of raising a child to adulthood almost require a support system of caring others if the child is to survive. In making this argument, Hrdy marshals a large array of research findings, at the same time managing to make them accessible and interesting to nonspecialist readers. Furthermore, Hrdy provides her own answer to the question of what defines humanity.
The fact that multiple caregivers are needed to raise a child means that, from their very early days, most young humans are exposed to many other people in addition to forming a primary bond with their mother. Some of these “others” around them offer attention, love, and food, backing up the mother’s provision of these necessities. Others may be indifferent, or even inimical to the child’s welfare. Hrdy suggests that the ability to “read” others’ intentions and states-of-mind must have been an essential survival skill that shaped humans’ future. The capacity to “mind read” other people, to know and care what other people think and to spontaneously share emotions as well as material objects with them, formed a basis for all later cooperative human ventures, from big-game hunting to creating such complex systems as representative government.
The book opens with a startling image: a plane full of chimpanzee passengers. Traveling in such company, the author says, any individuals would be lucky to finish the flight with all their fingers and toes intact. Despite their close genetic relationship to humans, chimpanzees seem to lack the “mental wiring” for spontaneous giving or to perceive others’ wishes and emotions. These capacities underlie the existence of hospitality, good manners, and moral codesconcepts that every human society has developed.
Studies of chimpanzee behavior have demonstrated how very protective the mothers are of their young. In all species of great ape, mothers form profound and long-lasting bonds with their infants. Normally, babies are in constant physical contact with their mothers for at least half a year. They cling to their mothers as they go about their daily rounds and continue to nurse for four to seven years. Other females around a mother will be greatly interested in her babya pattern true of all primatesbut an ape mother does not normally turn her infant over to any other primate to hold, much less to “baby-sit.” Indeed, a baby ape’s world is defined almost exclusively by his or her mother’s presence.
Human mothers’ experiences with their children are different. While the human mother-child bond may be just as profound and long-lasting as it is among primates, the human lack of fur and a mother’s need to do things with her hands make continuous body-to-body contact much less secure. Thus, human mothers are much more likely than primate mothers to allow other people to hold their babies, as well as to feed and amuse them. In hunter-gatherer societies, which follow a preagricultural mode of life, babies are never left alone, but mothers willingly let...
(The entire section is 1894 words.)