Uncertainty causes humans to use social heuristics and to cooperate more: An experiment among Belgian university students

Abstract

When humans engage in social interactions, they are often uncertain about what the possible outcomes are. Because of this, highly sophisticated cooperation strategies may not be very effective. Indeed, some models instead predict the emergence of ‘social heuristics’: simple cooperation strategies that perform well across a range of different situations. Here, we put these predictions to the test in a large-scale interactive decision making experiment. We confronted participants (mostly Belgian university students) with a broad range of cooperative interactions, systematically varying the uncertainty participants had about the consequences of cooperating. As expected, we find that uncertainty about the payoff consequences of cooperation causes individuals to use social heuristics. Additionally, these heuristics directly cause a marked increase in cooperation compared to the treatment without uncertainty, even in situations where cooperation can never be beneficial. These findings provide a new explanation for why human social behavior often violates the standard predictions of economic and evolutionary theory.