Why We Love Read Free Page A

four years apart. As a result, anthropologists think that four-year birth intervals were the regular pattern of birth spacing during our long human prehistory. 8
    Thus the duration of human birth spacing is similar to the general duration of worldwide marriages that end in divorce.
    So here’s my theory: perhaps like robins, foxes, and many other serially monogamous creatures, ancestral humans living some 3.5 million years ago paired with a mate only long enough to rear a single child through infancy—about four years. 9 When a mother no longer needed to nurse or carry an infant constantly and could deposit her baby with grandmother, aunts, sisters, cousins, and older youngsters while she gathered food, she no longer needed a full-time partner to ensure the survival of her child. Indeed she could “divorce” a mate if she found a new man more to her liking. Primitive divorce even had genetic payoffs: men and women who “remarried” could bear young with a different partner—creating beneficial variety in their lineages.
    “Trouble is only opportunity in working clothes,” wrote industrialist Henry J. Kaiser. As serial monogamy evolved over countless generations, I think this habitual human practice selected for the brain circuitry for short-term attachment. Along with this remarkable innovation came our human concepts of the “father,” the “husband,” and the nuclear family, our human tendency to become restless in long relationships, and our human penchant to depart a relationship and pair again: serial monogamy.
    But did this primitive tendency to form short-term partnerships spark the development of human romantic love?
    Perhaps it did. Perhaps the attraction that chimps and other creatures feel for a “special” mating partner became more intense and enduring as primitive men and women began to pair up to rear infants as a team. Then as this attraction slowly ebbed, feelings of intense attachment grew. When their child toddled out of infancy, however, I think many couples began to seek fresh love. A few parents may have remained together to have more children; many others sought new romance—unconsciously driven to bear more varied young.
    But the courtship process must have been rather simple some 3.5 million years ago. I say this because these australopithecines had a cranial capacity of some 420 cubic centimeters, only slightly larger than the average cranial capacity of chimps. And impressions left by brain tissue on the inside of these fossil skulls indicate that the regions for human language had not begun to grow. They did not speak in human ways. Moreover, these forebears left no drawings on rock walls, no homemade flutes or drums. They didn’t even make flint knives or any other kinds of stone tools for hunting—a hallmark of humankind. Our forebears had not developed the linguistic flair or other courtship tools humanity would come to flaunt. And it was in tandem with the evolution of all these magnificent human talents for wooing that I think human romantic love would bloom.
    To court, these australopithecine forebears must have depended on their status in the group, their chimplike wits and charm. They probably felt deep attraction to a mate, even remained attached to a mating partner for a few years. But many went on to court and love anew.
    “O Brave New World”
    The brave new world of humanness that Miranda wondered at in Shakespeare’s The Tempest started to appear some 2 million years ago. New people had begun to wander the open plains of what is today Kenya and Tanzania— Homo habilis , or handy man.
    Archaeologists have found heaps of their unfinished stone tools scattered across the plains of East Africa. 10 Generation after generation of Homo habilis peoples must have come to these quarry sites to make hammerstones, knives, anvils, and other tools, leaving behind slivers of flint and lumps of unfinished lava, obsidian, quartzite, and limestone. They weren’t highly skilled.