Incest avoidance and prohibition: psychobiological and cultural factors

Abstract

Although historically the incest prohibitive regulation is considered an almost ubiquitous cultural phenomenon that is not influenced by psychobiological factors related to the evolutionary history of human species, recent findings have challenged this traditional view and argued that the incest avoidance and prohibition are influenced by biological and cognitive factors along with cultural regulation. This article aims to develop a theoretical discussion about incest prohibition and avoidance, emphasizing the evolutionary mechanisms underlying these phenomena. One argues the existence of endogenous mechanisms that have evolved for inhibiting sexual activity between close relatives and form the basis to regulate the incest prohibition (exogenous mechanism) socially. The Westermarck effect is highlighted, in which the close proximity of persons living together from early childhood triggers sexual intercourse aversion between them. The absence of disposition to incest and its institutional prohibition represent a complex integration between psychobiological and cultural factors.