Why Menopause? (Part 2 of #makingmeaningofmenopause)

This is the second post in my “making meaning of menopause” series.

Why do humans have menopause, anyway? And what is it good for?

That’s the central question of historian Susan Mattern’s very comprehensive history of menopause, The Slow Moon Climbs.

I’m making my way through the book in chunks (did I mention how comprehensive it is?), and using that as the foundation for an ongoing inquiry into the meaning of menopause in my current context — as a middle age, north american White woman who’s never reproduced.

Here are the fascinating things I’ve learned in the first few chapters.

First, I love a good glimpse into the feverish arguments of a field I am at more than arms’ length from. Turns out historians and evolutionary biologists REALLY don’t agree on why human women* — unlike almost any other animal — long outlive their reproductive value. (NOTE: When I’m discussing the book, I’m using the term “women” in the way the author does, which is, so far, an unexamined assumption of binary gender where the people who menstruate and experience menopause are presumed to be cis-women in cultures that assume most such humans will become wives, mothers and grandmothers. I’ll talk more about the constructs of menopause in a more diverse understanding of gender in a later post.).

In her early chapters, Mattern exhaustively and convincingly explores the science about how long females in other species outlive their capacity to reproduce. And while there a few examples of creatures that stop reproducing and then perform a different, non-breeding function in their social worlds, humans are unique in the length of post-reproductive lifespan. (Well, there are aphids, who undergo a kind of menopause and then become selfless, self-sacrificing protectors of their colonies by flinging a sticky substance at attackers, to defend the colony at a cost to their own lives. But this kind of kamikaze protective role is anomalous).

Essentially (and I’m wildly oversimplifying here), evolutionary biologists recognize that post-reproductive human females play an important role in the development of long life spans in humans. The current prevalent theory (though also contested!) is the “grandmother hypothesis”: By being freed up from breeding and keeping small children alive, older women have been a critical part of the evolution of social groups by foraging for and growing food and supporting younger relatives. This ability to augment food supply, foster cooperation and support weak or ill members of a group is believed by many to have directly contributed to the increasing life span of humans over time, the evolution of skills and knowledge, the capacity to withstand climate cycles of drought and food scarcity, and the spread of humans across the globe: “once weaned children could be supplied with hard-to-acquire foods, it allowed humans to live in new environments and to colonize the world. Once adult lifespans lengthened, longer childhoods evolved as a result. Humans took advantage of these longer childhoods to develop higher levels of foraging skill; social skills also developed rapidly as cooperation became more important at all ages.”

The grandmother hypothesis points to menopause as an “evolutionary adaptive” strategy. By evolving a category of skilled, experienced adults who are not preoccupied with the keeping alive of babies or taking on the risks of childbirth, menopause is a critical part of the evolution of social worlds, human skills and knowledge, and human capacity to do more with their lives than simple survival.

There’s a nice overview of this hypothesis here.

(I’m not going to go into detail about the critiques of this hypothesis — most are grounded in thinking of menopause as an “epiphenomenon” of genetic changes — an accidental byproduct rather than an adaptation; a common theme is that evolution is competitive, with men needing to reproduce with a variety of younger women to ensure the propagation of the species; having older women around may be helpful, but isn’t a direct, desired adaptation).

So. If post-reproductive life evolved as a way for humans to have a life cycle that allows both intensive investment in offspring AND a large role for experience and the evolution of knowledge and technology, menopause is a transitional point to a different life stage. In forager cultures, this role might be elder, grandmother or mother-in-law. In our western industrial culture, what is the equivalent?

I’m going to leave this here for this week, with a question: what are your narratives about menopause? Do you see it as a transition to a potentially vital life stage? As a physical phenomenon and nothing more? Or as something (as more than one commenter put it last week) to fear or a reminder of not having “fulfilled” the expected role of reproduction?

How does the “grandmother hypothesis” influence how you think about menopause?

Fieldpoppy is Cate Creede, who is now on her fifth month without a period for the first time since 1977. Here she is with HER grandmother, learning to bake something, around that time.