Thank You, Grandma, for Human Nature

By Alison Gopnik Why do I exist? This isn’t a philosophical cri de coeur; it’s an evolutionary riddle. At 58 I’m well past menopause, yet I’ll soldier, on, with luck, for many years more. The riddle grows more vivid when you realize that human beings (and killer whales) are the only species where females outlive their fertility. Our closest primate relatives – chimpanzees, for example – usually die before their 50s, when they are still fertile. This isn’t just a …