Interdependent situations are pervasive in human life. In these situations, it is essential to form expectations
about the others’ behaviour to adapt one’s own behaviour to increase mutual outcomes and avoid exploitation. Social
value orientation, which describes the dispositional weights individuals attach to their own and to another person’s
outcome, predicts these expectations of cooperation in social dilemmas—an interdependent situation involving a
conflict of interests. Yet, scientific evidence is inconclusive about the exact differences in expectations between
prosocials, individualists, and competitors. The present meta-analytic results show that, relative to proselfs (individualists
and competitors), prosocials expect more cooperation from others in social dilemmas, whereas individualists
and competitors do not significantly differ in their expectations. The importance of these expectations in the decision
process is further highlighted by the finding that they partially mediate the well-established relation between social
value orientation and cooperative behaviour in social dilemmas. In fact, even proselfs are more likely to cooperate
when they expect their partner to cooperate
