Abstract

Previous theoretical accounts have predicted that warfare and intergroup conflict are environmental factors that contribute to the emergence of a fast life-history strategy. However, this assumption has never been directly empirically tested. We examined youth who grew up in a territory that experienced violent intergroup conflict and compared them with a control group on various life-history measures: age of first sexual intercourse, mating behavior, desired timing of marriage and first reproduction and desired number of children. We also measured other characteristics to explore the congruence between them and exposure to conflict. Participants from the postconflict society showed indications of faster life-history strategy: greater mating effort, a tendency to marry and have their first child sooner, and a larger desired number of children. Furthermore, interactions between exposure to conflict and participants’ sex were found: females from a postconflict society want to have their child earlier, and males have elevated short-term mating success. Finally, the exposure to violent conflict turned out to have congruent effects with economic poverty but not troublesome family relations. The findings are in accordance with life-history theory and show the adaptiveness of human behavior related to fitness optimization in hostile and dangerous environments.