emergence, transformation, diffusion and stabilization of forms of behavior.”3
Nash did not invent game theory, but he expanded its scope and provided it with more powerful tools for tackling real-world problems. At first, though, the depth of his accomplishment was little appreciated. When his revolutionary papers appeared, in the early 1950s, game theory briefly became popular among Cold War analysts who saw similarities between international aggression and maximizing profits. But within economics, game theory remained mainly a curiosity. “It didn’t take off,” the economist Samuel Bowles told me. “Like a lot of good ideas in economics, it just fell by the wayside.”4
In the 1970s, though, evolutionary biologists adopted game theory to study the competition for survival among animals and plants. And in the 1980s, economists finally began to use game theory in various ways, finding it especially helpful in designing actual experiments to test economic theory. By the late 1980s game theory had re-emerged in economics in a big way, leading to Nash’s 1994 Nobel.
Even before then, game theory had already migrated into the curricula of many scientific disciplines. You could find it taught in departments not only of mathematics and economics and biology but also political science, psychology, and sociology. By the opening years of the 21st century, game theory’s uses had spread even wider, to fields ranging from anthropology to neurobiology.
Today, economists continue to use game theory to analyze how people make choices about money. Biologists apply it to scenarios explaining the survival of the fittest or the origin of altruism. Anthropologists play games with people from primitive cultures to reveal the diversity of human nature. And neuroscientists have joined the fun, peering inside the brains of game-playing people to discover how their strategies reflect different motives and emotions. In fact, a whole new field of study, called neuroeconomics, has taken shape, mixing game theory’s methods with brain-scanning technology to detect and measure neural activity corresponding to human judgments and behavior. “We’re