New research on 100 primate species, including humans, suggests that everyday aggression and lethal violence may be governed by different evolutionary pressures. The study, described in ScienceDaily, compared patterns of mild aggression and killing across species to test whether they form a single behavioral spectrum.
Contrary to what that simple model would predict, the researchers found that species which frequently fight or show mild aggression are not necessarily the ones most likely to kill rivals. This dissociation suggests that lethal violence is not simply an extreme endpoint on a continuum of everyday aggression, but may have its own distinct evolutionary drivers.
The findings complicate the common narrative that humans are naturally predisposed to violence because of our primate heritage. While the study does not deny that humans are capable of violence, it suggests that the propensity for killing is not an inevitable byproduct of a generally aggressive nature. Instead, the conditions that lead to lethal violence may be more specific and context-dependent.