The snarls and sneers that keep violence at bay

The ability to mete out violence appears to be linked to survival in the animal kingdom. But a handful of researchers is now making a persuasive case that scores are settled far more often by subtle, nonviolent signals such as a curled lip or a snarl. Their provocative idea is that inflicting violence on a member of one's own species is a pathological condition that arises when these signals are missed or misinterpreted.