Why father absence might precipitate early menarche: The role of polygyny

An evolutionary model of conditional reproductive strategies argues that girls whose fathers are absent or make little parental investment experience early puberty. However, such a conditional strategy cannot be adaptive unless the absence of the girl's father at the microlevel is predictive of some recurrent feature of the macrosocial system and early puberty is advantageous in the system. I argue that father absence is indicative of the degree of polygyny (simultaneous and serial) in society. Polygyny of both kinds creates a shortage of women in reproductive age, and thus, early puberty will be advantageous. Available comparative data indicate that the degree of polygyny is associated with a decrease in the mean age of menarche across societies, as is the divorce rate a presumptive index of serial polygyny, in strictly monogamous societies.