Are Humans Peacocks or Robins?

Sociobiological approaches have made great inroads into psychological science over the last few decades. This hasn’t come without a fight. One of the main fronts on which the battle has been fought is the origins of human sex differences. Evolutionary psychologists have made a strong case that many basic sex differences in our species have an evolutionary origin; the case is now so strong, in fact, that it seems unreasonable to deny a significant evolutionary contribution. A question mark remains, however, over the relative magnitude of the evolved differences. Are we highly dimorphic, polygynous animals like peacocks? Or are we relatively monomorphic, pair-bonding animals like robins? In this chapter, I argue that we’re closer to the latter than the former - a fact that makes us somewhat anomalous among the animals. In many species, the males alone compete for mates and the females alone choose from among the males on offer. In our species, in contrast, both sexes compete for mates and both are choosy about their mates. Certainly, males compete more fervently and females are choosier, at least in early courtship and for low-commitment relationships. But the most conspicuous feature of the human mating system is mutual mate choice, coupled with relatively modest levels of overall dimorphism. Link to published version: https://www.cambridge.org/core/books/cambridge-handbook-of-evolutionary-perspectives-on-human-behavior/are-humans-peacocks-or-robins/83C55792A6FFB864AD46860FD0606692