On the Wason selection task with the Sharing-rule, there are three major response patterns; 1) to select those cards that detect resource-provider's non-cooperation to in-group, 2) to select those cards that detect resource-provider's failure to exclude out-group parasitism, and 3) to select the cards that detect both types of rile violation. We examined the relationship between the individual differences on the Sharing-rule Wason selection task and the participants' general trust level. Results showed lower general trusters tended to select the cards that detect resource-provider's failure to exclude out-group parasitism. The higher general trusters showed a tendency to select only the cards that detect non-cooperation by resource-provider. These results suggest that individual differences on social rule reasoning are related to respondents' perception, cognition, and attitude towards the social world.

Key words: Wason selection task, general trust, reasoning on social rule, individual differences