ゲーム理論
Social dilemmas have attracted a great deal of interest in the social and behavioral sciences. Economists, biologists, psychologists, sociologists, and political scientists alike study behavior in social dilemmas. The most influential theoretical approach is economic game theory (i.e., rational choice theory, expected utility theory). Game theory assumes that individuals are rational actors motivated to maximize their utilities. Utility is often narrowly defined in terms of people's economic self-interest. Game theory thus predicts a non-cooperative outcome in a social dilemma. Although this is a useful starting premise there are many circumstances in which people may deviate from individual rationality, demonstrating the limitations of economic game theory.