Men can get aggressive every month, particularly toward rugged, fertile looking chaps.
Rob Burriss, a biologist at the University of Liverpool, who led the study, said the behaviour reflected that of other primates: “Groups of animals, such as chimpanzees, can live quite happily together, but when a female is ready to mate the two dominant males within the group become rivals and fight for her attention.”
Technorati tag: Ovulation, Mating