cern for the welfare of others. “Further analysis of preferences of this type seems highly relevant for our understanding of many social behaviors,” Weibull observes.4
By getting a grip on the nuances of social preferences, game theory enhances its prospects for forging a science of human behavior, a Code of Nature for predicting social phenomena. But there might be a flaw in that plan. It presumes that there is such a thing as “human nature” to begin with for game theory to describe.
At first glance, experiments such as those using the ultimatum game do seem to provide evidence for a consistent human nature. After all, when economists play the ultimatum game with college students, the results come out pretty much the same, whether in Los Angeles, Pittsburgh, or even Tokyo. And of course, one wellknown battalion of social scientists argues strongly that there most definitely is a universal human nature. They are devotees of a discipline known as evolutionary psychology, a widely publicized field contending that human behavior today reflects the genetic selection imposed on the species during the early days of human evolution. Human nature, this notion implies, is a common heritage of the race, shaping the way people instinctively respond to situations today, based on how they behaved in order to survive in hunter-gatherer times.
A typical advocate of this view is Harvard psychologist Steven Pinker, who argued his beliefs with considerable passion in a book called The Blank Slate. Viewing the brain as blank at birth, to be shaped totally by experience, is nonsense, he insisted. General features of human nature have been programmed by evolution and stored on a genetic hard drive that guides the brain’s development. As a result, human nature today derives from the era of early human evolution. “The study of humans from an evolutionary perspective has shown that many psychological faculties (such as our hunger for fatty food, for social status, and for risky sexual liaisons) are better adapted to the evolutionary demands of our ancestral