First, there is the special case of genetic kinship. Second, there is reciprocation: the repayment of favours given, and the giving of favours in ‘anticipation’ of payback. Following on from this there is, third, the Darwinian benefit of acquiring a reputation for generosity and kindness. And fourth, if Zahavi is right, there is the particular additional benefit of conspicuous generosity as a way of buying unfakeably authentic advertising.
