Why Zebras Don't Get Ulcers: The Acclaimed Guide to Stress, Stress-Related Diseases, and Coping

by Robert M. Sapolsky

Social primates do this all the time. However, among hyenas, an erection is a sign of social subordinance. When a male is menaced by a terrifying female, he gets an erection—“Look, I’m just some poor no-account male; don’t hit me, I was just leaving.” Low-ranking females do the same thing; if a low-ranking female is about to get trounced by a high-ranking one, she gets a conspicuous clitoral erection—“Look, I’m just like one of those males; don’t attack me; you know you’re dominant over me, why bother?” If you’re a hyena, you get an erection when you are stressed. Among male hyenas, the autonomic wiring has got to be completely reversed in order to account for the fact that stress causes erections. This hasn’t yet been demonstrated, but perhaps Berkeley scientists working on this, squandering tax dollars that could otherwise be going to Halliburton and Bechtel, will do it. Thus the hyena stands as the exception to the rule about erectile functions being adversely affected by stress, a broader demonstration of the importance of looking at a zoological oddity as a means of better seeing the context of our own normative physiology, and a friendly word of warning before you date a hyena.