Female primates carry and nurse the fetus, and thus have the first responsibility for rearing the offspring. Assuming males are at least equally adept at obtaining food, males might either share surplus food with females or consume the food themselves. The distribution of this surplus is the...

As female primates carry and nurse the fetus, it naturally falls on them to rear the offspring. On the assumption that males are at least equally adept at obtaining food, it follows that they generate a surplus which they might either share with females or consume themselves. This choice lies at...