Trust in the brain

Abstract

What determines how humans interact socially? Why do we sometimes cooperate but at other times refuse to act cooperatively? Why are some people willing to trust a stranger, whereas others are mistrustful? Why do some people take risks to achieve their goals, whereas others prefer to stay on the safe side? Answering such questions will eventually help both social scientists and biologists to unravel the mechanisms that guide the social interactions of Homo sapiens , with potentially wide‐ranging implications for human life. In the past few decades, social scientists have made much progress in understanding the mechanisms of human social interaction and cooperation. Their main analytical tool, game theory, has been useful in widely varied disciplines such as economics, psychology, sociology and political science. Owing to the nature of these fields, most of the questions that social scientists ask focus on the external social, environmental and institutional determinants of human behaviour; the internal biological mechanisms underlying and regulating individual decision‐making, however, have been treated more or less as a ‘black box’. At the same time, the neurosciences have long avoided explicitly modelling human social interactions. Interestingly—and I believe fortunately—this has changed recently. With the emergence of new fields such as neuroeconomics and social cognitive neuroscience, scientists have begun to look into the black box that guides human decision‐making in social contexts. Their main approach is to combine methods from both the social sciences and neuroscience to understand how the human brain generates decisions. Game theory is now used to analyse the human brain in conjunction with a variety of scientific techniques, including functional magnetic resonance imaging, transcranial magnetic stimulation and intranasal administration of neuropeptides. In this article, I provide some insights into this interdisciplinary research by describing a particular game—the trust game—that has been used successfully to study the neurobiology …