Robert M. Sapolsky is a professor of biology and neurology at Stanford University and a research associate with the Institute of Primate Research, National Museum of Kenya. He is the author of Why Zebras Don't Get Ulcers, A Primate's Memoir and The Trouble with Testosterone, which was a Los Angeles Times Book Award finalist. A regular contributor to Discover and The Sciences, and a recipient of a MacArthur Foundation "genius" grant, he lives in San Francisco.