Murder by Design: The Evolution of Homicide

We propose Homicide Design Theory as a new theory to explain why people kill. Multiple homicide mechanisms have evolved as effective context-sensitive solutions to distinct adaptive problems. Killing historically conferred large fitness benefits: preventing premature death, removing rivals, gaining resources, depriving rivals of mates, aborting rival’s prenatal offspring, eliminating stepchildren, and winnowing future competitors of one’s children. Homicidal premeditations are part of evolved killer design, functioning to mobilize attention, rehearse scenarios, calculate consequences, and motivate behavior. Because getting killed inflicts temporally cascading costs on victims, selection has forged anti-homicide defenses, producing coevolutionary arms races between homicidal strategies and anti-homicide defenses.