Male care and mating effort among Hadza foragers

Paternal care figures prominently in many scenarios of human evolution. Rec ently, however, such scenarios have been challenged on two scores. First, t he level of male contribution may be insignificant. Second, male care may b e provided as a form of mating effort, rather than parenting effort. In the ory, since men can enhance their Darwinian fitness both by providing care t o their own offspring if this raises offspring fitness and by pursuing addi tional mates if this leads to additional offspring, men should respond to p ayoffs from both mating and parenting effort. If men respond to payoffs fro m parenting effort, paternity ought to make a difference. And if men respon d to payoffs from mating effort, mating opportunities ought to make a diffe rence. I analyzed the impact of these two factors on variation in male care among the Hadza, a foraging society in Tanzania. Two predictions were test ed: (1) biological children will receive more care than stepchildren, and ( 2) men will provide less care to their biological children as their mating opportunities increase. Both predictions were supported. These results sugg est men provide care, in part, as parenting effort, and that they trade off parenting effort for mating effort when they have greater mating opportuni ties.