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Artist, Heather Oliver             

Grandmothers Raise Civilizations

Several attributes of human women are routinely posited as evolutionary enigmas because they tend to be placed in the “not really necessary” and/or “inconvenient” bins: hidden ovulation (How’s a guy to know a kid is his?? Ergo, chastity belts and purdahs!); orgasms (Who cares, as long as the kids come out?); and living past menopause (Done with heir production and no longer eye candy — discard!).

However, it turns out these attributes are not that enigmatic unless you believe that teleology drives evolution. It looks increasingly like the bright red buttocks of our primate relatives are actually a recent acquisition, and hidden ovulation is the earlier default. Some cultures have solved the kinship problem: brothers act as fathers to their sisters’ children, to whom they are unequivocally related. Orgasms are equally explicable once you accept the simple fact that the clitoris is the equivalent of the penis, including the associated excitability and sensitivity (which is why female genital mutilation is identical to a penectomy, not to foreskin circumcision). As for living longer than the contents of one’s ovaries, which is a third of women’s lifespan once they’re past the risky childbirth years, it may have to do with what made us human in the first place. So says the grandmother hypothesis, first intimated by George C. Williams of antagonistic pleiotropy fame and later elaborated by Kristen Hawkes and her colleagues in the late nineties, after observations of the Hadza people in Tanzania.

Back in the fifties and in today’s evo-psycho groves, the fashion has been to posit the nuclear family as the kernel unit of primordial humanity. If you take the crucial details of humans into account (unique birth risks, extended neoteny, unusual nutritional requirements, necessity for higher-order skill acquisition), you realize that the possibility of such a unit seeing offspring reach adulthood is close to nil. Not surprisingly, when anthropologists look carefully and past their own cultural blinders at less technologically endowed human groups, the scaffolding they see is always communal. As Sarah Blaffer Hrdy said, it really does take a village to raise a child.

Such a configuration is not problem-free: it’s vulnerable to tyranny of conformity as well as the devastation that can be wrought by charismatic sociopaths. Nevertheless, it allows distribution of infant care, overlap of skills, quasi-fair apportioning of resources and monitoring of emerging imbalances. And grandmothers, maternal ones in particular, play a crucial role in all of these.

The grandmother hypothesis postulates that the presence of grandmothers allowed more children to reach adulthood, because grandmothers not only foraged for their daughters’ older offspring but also socialized them, taught them important skills and transmitted knowledge and experience. It also postulates that older children had to develop ways to compel caretaker attention, giving rise to the enlarged frontal lobe unique to humans. So the hypothesis argues that female longevity is essentially a “quality over quantity” fitness adaptation that in turn favored descendants of women who fit this profile.

There is, of course, a competing hypothesis far more beloved of Tarzanists. The hunting hypothesis, demolished by Sally Slocum, postulates that hunting became better than foraging as a means of sustenance when resources became scarcer in Africa; and that coordinating the hunt (versus, say, figuring out which berries weren’t poisonous) led to natural selection for bigger brains as well as ushering in the female adoration of “alpha males” who brought home the only protein that supposedly counts.

Kristen Hawkes recently published the results of a mathematical simulation of the grandmother hypothesis. The algorithms did not include brain size, hunting or pair bonding. The model showed that grandmother effects alone are sufficient to double life spans in less than sixty thousand years. Not surprisingly, one requirement is natal homing: living close enough to the maternal grandparents that grandmothers can exert their humanizing effects. This fits with the observation that rigidly patrilocal and patrilineal societies which completely obliterate female kinship networks have often gone for quantity over quality, essentially reducing women to incubators that can always be exchanged for newer models – and that some of these societies used to discard infant girls and older women literally like garbage. Other societies went the opposite route, treating older women like honorary almost-men (allowing them to keep sacred objects, for example, though few were made council heads) once they were no longer “tainted” by menstruation.

Those who had grandmothers almost certainly remember the stories they told and the moderating influence they exerted on the family. I never met either of mine. Both died young; tuberculosis hollowed one, fire consumed the other. I did get to know my father’s stepmother, a gentle too-religious soul who was one of the first Greek women to become a teacher. She tried her best, but was not strong enough to counteract my mother’s fierceness, which I have internalized by now. I wonder if I would have been more adjusted to social expectations had my other grandmothers been around, wielding the authority of blood kinship. Given my other non-adaptive core attributes, I suspect the answer is no.

Selected papers:

Slocum, Sally. (1975, reissued 2012). Woman the Gatherer: Male Bias in Anthropology. In Anthropological Theory: An Introductory History. R. Jon McGee and Richard L. Warms, eds. Pp. 399-407. New York: McGraw-Hill.

Hawkes, Kristen. (2003). Grandmothers and the evolution of human longevity. American Journal of Human Biology 15 (3): 380–400.

Images: 1st, Grandmother Storyteller by Ada Suina (Wheelright Museum, Santa Fe, NM); 2nd, Pakistani grandmother with her three-day-old grandchild (credit: Adek Berry, AFP).

9 Responses to “Grandmothers Raise Civilizations”

  1. Walden2 says:

    I consider my mother’s mother to have been my second mother, as she was there for me when both my parents worked (at a time when that was still not the norm it is today) while growing up and dealing with other issues. I honestly do not know what would have become of me and my sister in certain respects without her presence (and my grandfather’s, I might add, as he tried to teach me certain other skills about growing up as a man).

    Thank you for showing us outside the box again, Athena. I know it can seem a thankless job, but paradigms do change even if slowly once it is introduced long enough into society. I have seen such changes in attitude and thinking in my lifetime.

  2. Athena says:

    You’re very welcome, Larry! I think grandparents are essential for working mothers — and mothers have worked for 99% of the time across eras and cultures (if we define “work” as additional work outside the confines of the house; of course, the latter is a full-time job itself).

  3. Walden2 says:

    Yes, sorry I did not clarify: My mother worked outside the home as well as an elementary school teacher. My grandmother, while not having a job with an actual paycheck et al, grew up on a farm so she worked very hard since she was a little girl.

  4. Lars says:

    Actually, the only story that my one surviving grandmother ever told me was the one about the Babes in the Woods. The moral of which, she seemed to imply, was that small children wound up getting lost in the woods and dying of exposure at times, but small birds would come and cover them over with leaves when this happened.
    I have spent decades wondering why anyone would tell a small boy this and what I was supposed to make of it. Now I realize that it very likely was passed on orally to her and shows how long folk-stories concerning regicide can last in an oral culture.

  5. Athena says:

    There are plenty of scary stories (all fairytales were far bloodier before they became “safe”). The fairytales I heard/read as a kid contained graphic abuse, rapes, grisly deaths…

    Also, teaching fear and wariness is part of socializing.

  6. Michael says:

    My wife is from China and was raised by her grandmother, and it was agreed to from the earliest days of our courtship that her parents would come to live with us. There is no way we would have been able to achieve the level of material wealth we have now if not for having my wife’s parents to raise our kids while we ran our businesses.

    I wonder if anyone has done a study of how economically draining a nuclear family is compared to an extended family. If you have to pay for daycare, then basically, mom is working for the daycare company. If grandma is taking care of the kids, then mom’s paycheck can benefit the entire family and will result in more value in the long run than if dad, mom, and grandma each work outside of the home and have to pay others for daycare, cooking and home maintenance.

  7. Athena says:

    Elizabeth Warren quotes such studies in her very informative talks. Of course, the extended family has its own problems (especially if it’s patrilocal).

  8. Walden2 says:

    My grandmother told me stories about the Gypsies who would come wandering through her agricultural (read rural) community in their wagons as a child (circa 1910). Her parents warned my grandmother never to get near them, as the Gypsies would grab her and take her away to be eaten later.

    In reality the Gypsies did often stop to ask for food, but of the non-human variety. One time when my great-grandmother was newly married she gave a Gypsy woman something to eat, the woman told my GG her fortune in gratitude. She said my GG would have first a son and then a daughter, and that would be all her children.

    Turns out the Gypsy woman was right. Then my GG went and had eight more kids after that!

  9. [...] of life”: It is just so cool! And Athena Andreadis has a lovely post on human evolution and The Grandmother Hypothesis: “that the presence of grandmothers allowed more children to reach [...]