Social responsibility promotes conservative risk behavior

•We study how risk taking is affected by social context in a lottery choice experiment.•Social responsibility leads to conservative risk behavior in group decision making.•If only informed about others' risk taking, subjects conform with others' choices.•Risk taking is not linked to simple measures of distributional fairness under certainty.

Previous studies show that group risk taking can be more conservative than individual risk taking. Two common, but untested reasons for this greater caution are the influence of social responsibility and a tendency to conform to the preferences of others. We study changes in risk taking in simple settings, where another's risk taking can sometimes be observed, and where decisions affect not only one's own payoffs but sometimes also affect those of a passive, second party. We find that social responsibility leads to more conservative risk behavior in group decision making. Conformism has a more symmetric effect: observing the choice of another tends to lead both individual and social decisions toward whatever the other's expressed risk preference is. Direct tests fail to link the social behavior we observe to the social preference for distributional fairness common in decision-making under certainty.