Official websites use. Share sensitive information only on official, secure websites. When one individual helps another, it benefits the recipient and may also gain a reputation for being cooperative.
This may induce others to favour the helper in subsequent interactions, so investing in being seen to help others may be adaptive. The best-known mechanism for this is indirect reciprocity IR , in which the profit comes from an observer who pays a cost to benefit the original helper.
IR has attracted considerable theoretical and empirical interest, but it is not the only way in which cooperative reputations can bring benefits. Signalling theory proposes that paying a cost to benefit others is a strategic investment which benefits the signaller through changing receiver behaviour, in particular by being more likely to choose the signaller as a partner. This reputation-based partner choice can result in competitive helping whereby those who help are favoured as partners.
These theories have been confused in the literature. We therefore set out the assumptions, the mechanisms and the predictions of each theory for how developing a cooperative reputation can be adaptive. The benefits of being seen to be cooperative may have been a major driver of sociality, especially in humans. Helping involves one individual paying a cost to benefit a recipient. The costs can be repaid in terms of indirect fitness if the helper and recipient are genetically related [ 1 ], or they can be repaid directly, for example if the recipient reciprocates [ 2 , 3 ] or if the helper has a stake in the recipient's welfare [ 4 — 6 ].
Another way helpers might increase their direct fitness is by gaining a reputation for being helpful. As a result, investing in a reputation for being seen to help others may be adaptive.
