As the 20th century progressed, both Freudianism and behaviorism faded. The black box concealing the brain turned translucent as molecular medicine revealed some of its inner workings. Nowadays the brain is almost transparent, thanks to a variety of scanning technologies that produce images of the brain in action. And so the infant neuroscience that Freud abandoned over a century ago has now matured, nearly to the point of fulfilling his original intention.
Freud could not have dreamed about merging neuroscience with economics, though, for he died before the rise of game theory. And even though they regarded game theory as a window into human behavior, game theory’s originators themselves did not imagine that their math would someday advance the cause of brain science. The original game theorists would not have predicted that game theory could someday partner with neuroscience, or that such a partnership would facilitate game theory’s quest to conquer economics.1 But in the late 1990s, game theory turned out to be just the right math for bringing neuroscience and economics together, in a new hybrid field known as neuroeconomics.
One of the appealing features of game theory is the way it reflects so many aspects of real life. To win a game, or survive in the jungle, or succeed in business, you need to know how to play your cards. You have to be clever about choosing whether to draw or stand pat, bet or pass, or possibly bid nillo. You have to know when to hold ’em and know when to fold ’em. And usually you have to think fast. Winners excel at making smart snap judgments. In the jungle, you don’t have time to calculate, using game theory or otherwise, the relative merits of fighting or fleeing, hiding or seeking.
Animals know this. They constantly face many competing choices from a long list of possible behaviors, as neuroscientists Gregory Berns and Read Montague have observed (in language