Breasts: Their Evolutionary Origins as a Deceptive Signal of Need for Provisioning and Temporary Infertility
Edward M. Miller Professor of Economics and Finance

Female Rewarding of Male Provisioning During Lactation
Even in existing apes food provision can be rewarded with sexual access. Females appear to reward with copulations males who feed them, even having been seen to take meat from the mouth of the male copulating with her (Goodall, 1986, 483-484). Estrous females succeed more often at begging meat from males than non-estrous ones (Goodall, 1986, 483-484). Kano (1979) describes how bonobos (pygmy chimpanzees) presented and copulated with males with fruits they wanted. Once hominids had adopted hunting, males frequently found themselves with meat which could be distributed to females. Males naturally distributed this meat to females who in turn gave them sexual access. [para 22]