The biological roots of heat-of-passion crimes and honor killings.

"Heat-of-passion crimes" are committed by jealous men against supposedly unfaithful mates, "honor killings" by vengeful relatives against female family members who have disgraced them. These terms are imprecise, and they overlap greatly in usage, but they are similarly, and troublingly, guilt-mitigating. Heat-of-passion crimes and honor killings are universally reported yet vary in incidence culture-to-culture. While typically among the most violent of domestic attacks, they are to different degrees protected in law. Nearly every culture has, or until recently has had, defenses to male culpability based on the supposed effects of provocation. The invention and persistence of these defenses needs explanation. This paper considers a biological perspective, in which heat-of-passion crimes and honor killings are understood as maladaptive byproducts of an evolved male sexual aggression subject to intensification by external threats to paternal certainty. Moral and procedural implications of this perspective, as well as its limitations, are discussed.