The present study stems from three general assumptions about prosocial behav-iour: a) that it has an evolutionary foundation; b) that it is sensitive to the inter-personal context in which it takes place; and c) that it can be supported by different values and motives. An experiment based on the Dictator Game (DG) was carried out, in which two groups of participants with different Social Values Orientation (SVO) established how to share either €30 gain and a €30 loss, also considering the varying intentions of the other, which could have been selfish, fair or altruistic. Results confirmed that other’s selfish intentions gave rise to a lesser sharing, while other’s fair/altruistic intentions were reciprocated with a balanced sharing. However, when sharing a loss, Proself participants tended to exploit the altruistic intentions of the other. Moreover, the analysis of the relevant motivations in the decisions showed that only an individual orientation towards fairness predicted a higher resource allocation; more specifically, sharing a loss when the other showed altruistic intentions was found to be a matter of fairness. These results support the evolutionary hypothesis that fairness, as a key feature of peer cooperation, offers an interpersonal motivational framework more conducive to prosocial behaviour than empathy-based altruism, which is a key feature of the caregiving/care-seeking interpersonal motivational framework.