Too many men: the violence problem?

There is a strong intuitive expectation in both popular lore and conventional evolutionary thinking that more males lead to more violence. Here, we untangle the logic behind this widely held notion with a specific focus on humans. We first review the relation between the intensity of sexual selection in human populations and the adult sex ratio (ASR), and find that it is more in line with recent reformulations of sexual selection theory than with conventional models. We then turn directly to the patterning of violence across human societies in relation to the sex ratio. Although the 'more men, more violence' expectation is not met, it is clear that the patterning of violence is undertheorized and we offer recommendations for steps forward.