People who are willing to take risks despite not knowing how likely it is that the risk will pay off, are also more likely to co-operate with and trust other people, suggests a study published this week in Nature Communications.

Psychologists and economists have previously identified two kinds of uncertainty: risk (in which the probability of each future outcome is known) and ambiguity (in which the odds of each outcome are not known). Individuals are known to differ in their tolerance to these two different kinds of uncertainty.

In this study, Oriel FeldmannHall and colleagues performed a series of experiments in which a total of 200 volunteers (106 female and 94 male participants) first completed a solo gambling game to assess their risk and uncertainty tolerance. They then played social games in which they had to decide whether to cooperate with other players. Co-operation potentially benefited both players but co-operators risked being betrayed and losing out. The results showed that ambiguity tolerance was positively correlated with the amount of prosocial behaviour. By contrast, there was no association between risk tolerance and social decision-making.

The authors suggest that we treat the decision to trust others as equivalent to a gamble where we do not know the odds, and that the personality trait of ambiguous uncertainty tolerance helps facilitate our social behaviour.