Most animals, from shrimp to shrews, decline swiftly after reaching sexual maturity. Humans, on the other hand, experience middle age: a several-decade plateau during which most biological systems deteriorate very little. This stage of life, argues writer and zoologist David Bainbridge in this excerpt from Middle Age: A Natural History, represents a remarkable evolutionary achievement that should gratify, not depress.
Yes, we need reading glasses to read and to inspect our sagging jawlines, but breeding is behind us, brains work fine, and learning continues. The middle aged cooperate, innovate, and contribute much of the skilled labor that life in an information society requires. “These changes strongly suggest that middle age is a controlled and preprogrammed process not of decline but of development,” Bainbridge writes. Instead of wannabes worried about wear and tear, “middle-aged people may be seen as . . . an elite caste of skilled, experienced super-providers on which the rest of us depend.”
What’s my beef? I’m irked by the defensive nature of his basic argument, although it’s understandable given the prevailing dismal view of life-after-youth. That’s what makes his an uphill battle, despite the many benefits the middle years convey: earning capacity, mobility, sexuality, kids newly independent and parents still so. My bigger beef is that Bainbridge has kicked the ball down the field but nowhere near far enough. He makes a fine case for the value of middle-aged humans “as super-providers and master culture-conveyers,” but after midlife? Only decline. Mid-life is desirable partly because late life appears much less so. His is still a deficit model that benefits one generation at the expense of another. Middle-aged people might not be “evolutionarily crucial” like young adults, he says, but neither are they “evolutionarily irrelevant” like old adults.
True, evolution has had some 65-100,000 years in which to make middle age “relevant,” while human lifespans have lengthened significantly only in the last century – a blink of an eye in evolutionary terms. It will take millennia for natural selection to shape this transition. That may render olders “evolutionarily irrelevant,” but late life is no less a socially and culturally constructed period of development than adolescence or middle age. Olders are well suited to the central task of modern life as envisioned by Bainbridge: the propagation and transfer of complex information. Instead of letting ageism blind us to this potential, we need to envision the institutions and structures that will support it, and in so doing benefit people of all ages.