The Behavioral Ecology of Male Violence by William Buckner.
Understanding patterns of lethal violence among humans requires understanding some important sex differences between males and females. Globally, men are 95 percent of homicide offenders and 79 percent of victims. Sex differences in lethal violence tend to be remarkably consistent, on every continent, across every type of society, from hunter-gatherers to large-scale nation states. In their 2013 study on lethal violence among hunter-gatherers, Douglas Fry and Patrik Söderberg’s data showed that males committed about 96 percent of homicides and were victims 84 percent of the time. In her study on violence in non-state societies, criminologist Amy Nivette shows that, across a number of small-scale pastoralist and agriculturalist societies, males make up 91-98 percent of killers. To illustrate the consistency of this relationship even further: we see the same pattern among chimpanzees, where males make up 92 percent of killers and 73 percent of victims.