Here is what the late Prof. Marvin Harris formerly of Columbia and Florida State Universities has to say in his book Our Kind:
"I would like to be able to say more about what kind of mating system and family organization prevailed during the formative phases of hominid social life. Over the entire span of four or five million years that separate us from the first afarensis, there is not a single piece of hard evidence bearing on this question. And the record is equally blank when it comes to post-takeoff Stone Age sapiens hunter-gatherers. This lack of evidence has not deterred various scholars from attempting to identify the form of mating to which all hominids are supposedly innately predisposed. Much popular support can always be found for those who insist the first humans were monogamous and that they lived in troops or bands composed of several nuclear fàmilies, each in turn consisting of a mated pair and their children. The logic behind this view is that human sexuality with its personalized, eye-to-eye, frontal orientation naturally leads to strong bonds between one man and one woman. Such pair-bonds supposedly provide the best assurance that human infants will be fed and nurtured during their long period of dependency. Some anthropologists like to round out this scenario by postulating a connection, between monogamy and the existence of a home base. Wife and child supposedly stay near the home base while husband/father goes off to hunt at a greater distance, returning at night to share the catch.
While I agree that exchanges of food and sex would lead to the development of stronger bonds between some males and some females, I do not know why these would have to be exclusive pair-bonds. What about contemporary mating patterns? Do they not show that alternative modes of mating and family organization are perfectly well suited to the task of satisfying human sexual needs and rearing human children? Polygyny is an ideal in more societies than is monogamy. And it occurs among foraging societies as well as among state-level societies. Moreover, as a result of the high frequency of divorce, of keeping mistresses and concubines, and having “affairs,” most ideologically monogamous societies are behaviorally polygamous. Let’s be realistic. One of the fastest growing forms of family in the world today is the single parent family headed by a woman. Sexual practices that go along with this family often correspond to a form of polyandry (one female, several males). In U.S. central cities and throughout much of South America, the Caribbean islands, and urbanizing parts of Africa and India, women have temporary or visiting mates who father the woman’s children and contribute marginally to their support.
In view of the frequent occurrence of modern domestic groups that do not consist of, or contain, an exclusive pair-bonded father and mother, I cannot see why anyone should insist that our ancestors were reared in monogamous nuclear families and that pair-bonding is more natural than other arrangements.
I am equally skeptical about the part of the pair-bond theory that postulates a primordial home base tended by homebody females whose males roamed widely in search of meat. It seems to me much more likely that afarensis and habilis males, females, and infants moved together across the land as a troop and that females who were not nursing took an active part in dispersing scavengers, combating predators, and in pursuing prey animals. My evidence? Women marathon runners. Competing against men in grueling twenty-six-mile races, they are steadily closing the gap between male and female winners. In the Boston Marathon, the women’s record of 2:22:43 is only 9 percent off the men’s record. This is scarcely the kind of performance of a sex whose ancestors stayed home minding the babies for two million years.
What I have just been saying should not be taken to mean that our presapiens forebears never formed monogamous pair-bonds. The point is simply that they were no more likely than modern-day humans to have mated and reared children according to a single plan. Given an ability to mediate potentially disruptive social arrangements by exchanging services for goods, goods for goods, and goods for services, our presapiens ancestors could have adopted mating and childrearing systems as diverse as the systems that exist today or that existed in the recent past."
I’m far from an expert in the subject but Dr. Harris spent a lifetime studying such matters and is worth listening to.
) on whether this social arrangement increases the fitness of its members. I think given fertility rates in western countries vs. non-western countries, a strong case could be made that it does not.