MONKEYLUV

Eighteen quick-footed essays that explain how nature and nurture are both vital ingredients in the stew of life.

Why, asks biologist/neurologist Sapolsky, do we do the things we do? Is it because of the imperative trajectory of our genes, which command without regard to environmental manipulations? Or does nurture trump genetic engineering? Neither and both, he says in these avuncular, dignified and scientifically astute pieces, their prose polished like silver, their humor stealing upon the reader like a merry prankster. Too much evidence exists, in short, to dismiss one or the other. Yes, there is genetic inevitability—red hair, for example, or Huntington’s disease—and, yes, there are examples of nurture swaying genetics, as in social conditioning and environment. The elegance is in the genetic-environmental dance, the way one gains the upper hand and is then countered by a response from the other. Sapolsky demonstrates how change in levels of hormones, nutrients or immune factors can prompt changes in how the brain thinks and emotes. Contrariwise, he details the extraordinary resilience of exported cultural baggage into new surroundings, as when a desert mind-set is plunked down in the Alps (though the rain forest mind-set appears to be less hardy when uprooted, perhaps because its peaceful-through-bounty nature is given a good stabbing). He elucidates the brain-body interactions, including dreams, postponing gratification, overreactions, stress disorders and the truly creepy MBP—Munchausen’s by proxy—in which a parent fabricates symptoms in a child. Then, smoothly, he shows how genes can modulate the way one responds to the environment. Ever entertaining, Sapolsky is always happy to explore such questions as at what age the window of receptivity shuts for, say, new music or a tongue stud or a genital ring.

It isn’t a radical notion that the nature-nurture debate ought to be tossed, but Sapolsky (A Primate’s Memoir, 2001, etc.) has added another round to the cause of its demise.