Shadows of Forgotten Ancestors

The celebrated philosopher Henri Bergson—an exponent of the “revolt against reason” and best known for the idea that some immaterial “vital impulse” permeates life and makes evolution go—wrote that “man … is alone in realizing that he is subject to illness.”³⁹ But chimps have a vast pharmacopoeia all around them, and a kind of folk or herbal medicine. For example, for chimps both at Gombe and at Mahale, leaves of a plant called

Aspilia are a kind of dietary staple, preferentially eaten in the early morning. Despite the wrinkled noses of those partaking (the taste is bitter), it’s consumed by both sexes, all ages, the healthy as well as the sick. But there’s something odd about it: The chimps eat these leaves regularly, but consume very few of them at any one time—so their nutritional value is in doubt. In the rainy season, though, when apes are plagued by intestinal worms and other illnesses, ingestion increases dramatically. Analysis of Aspilia

leaves reveals the presence of a powerful antibiotic and an agent that kills nematodes. It’s a good guess they’re treating themselves. Among other examples, a chimp sick with an intestinal disorder ingested large amounts of the shoots of a plant, different from Aspilia and not ordinarily a part of its diet, which also proved to be rich in natural antibiotics.

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How is “chimpanzee ethnomedicine” possible? Could it be based on some kind of hereditary information: You feel sick and suddenly you have a craving for a leaf whose shape or aroma is implanted in your brain from the beginning—like the goslings who are said to be born with a hereditary fear of the silhouette of a hawk? Or, more probably, is this cultural

information passed on—by emulation or instruction—from generation to generation, and subject to rapid change if the available medicinal plants change, or if new diseases arise, or if new ethnomedical discoveries are made? Except that there are apparently no professional herbalists or medical specialists among the apes, chimpanzee folk medicine does not seem so different from human folk medicine. There’s a common complaint for which everyone knows what medicine to take. It’s something you learn as you grow up. Why the medicine works is a mystery to them—as it still is, in many cases, to us.

Some scholars have imagined that sexual repression was the first and inaugurating facet of human culture.⁴¹ Unrestrained expression of sexual desire—especially among young men and women—will destroy the framework of society, it is suggested, so early human cultures must have placed severe restraints on sexual activity, and encouraged guilt, modesty, hard work, cold showers, and clothing. However, there are many human cultures, often in the tropics, with frameworks apparently uncompromised by the fact that adults go around unselfconsciously stark naked—or perhaps with a thin vine or cotton belt that conceals no sexual parts. In South America, Yanomamo women are wholly unclothed, except for such a belt; the men tie their foreskins to their belts (although they are embarrassed should the penis slip free).⁴² In New Guinea and elsewhere, men cover up by wearing gourd sheaths that immodestly exaggerate their proportions. Before the Europeans arrived, the aboriginal peoples of Australia, even those in chilly climates, wore no clothes at all. In ancient Greece, Egypt, and Crete, adult nakedness was common, at least for slaves and athletes (although women spectators were excluded from the Olympic games on the grounds that it would be immodest for them to watch male athletes competing in the nude). Nudist camps seem to be models of decorum. Restraints on the permissible can be much less severe than the more repressive cultures ever imagine—as Captain James Cook’s crews discovered in Tahiti.

Victorian sexual attitudes are clearly not characteristic of our species. Moreover, sexual jealousy is a common cause of domestic violence among monkeys and apes; despite their more relaxed sexual standards, they have inhibitions in place. All primate societies, humans and everyone else, set limits on acceptable practice. Sexual repression and associated feelings of shame cannot be the hallmark of our species.