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

by Robert M. Sapolsky

They claim they’re not depressed or anxious, and the psychological tests they are given show they’re right. In fact, they describe themselves as pretty happy, successful, and accomplished (and, according to personality tests, they really are). Yet, these people (comprising approximately 5 percent of the population) have chronically activated stress-responses. What’s their problem? Their problem, I think, is one that offers insight into an unexpected vulnerability of our human psyche. The people in question are said to have “repressive” personalities, and we all have met someone like them. In fact, we usually regard these folks with a tinge of envy—“I wish I had their discipline; everything seems to come so easily to them. How do they do it?” Clifford Goodenough, Figure Walking in a Landscape, goldleaf tempera, oil on masonite, 1991. These are the archetypal people who cross all their t’s and dot all their i’s. They describe themselves as planners who don’t like surprises, who live structured, rule-bound lives—walking to work the same way each day, always wearing the same style of clothes—the sort of people who can tell you what they’re having for lunch two weeks from Wednesday. Not surprisingly, they don’t like ambiguity and strive to set up their world in black and white, filled with good or bad people, behaviors that are permitted or strictly forbidden. They keep a tight lid on their emotions. Stoic, regimented, hardworking, productive, solid folks who never stand out in...