Abstract
Avoiding sex with relatives alias incest is considered to be auniversal phenomenon. Individual disciplines, however, differ in their explanation of the emergence of incest avoidance.
This review aims to introduce the theories of incest avoidance from the point of view of cultural and evolutionary anthropology and thus contribute to the understanding of the complex phenomenon. The reason for the low occurrence of incest might be the existence of the incest taboo - the established social norms and conventions that prevent incest.
However, the universality of the incest taboo is limited only to the nuclear family; the incest taboo with respect to wider kin has high cultural variability. The low occurrence of incest might also be a consequence of the so-called Werstermarck effect, i.e., the emergence of sexual aversion among individuals that grew up together (usually relatives), empirical studies show that individuals that grew up together in close contact until approximately six years old are not attracted to each other.
Therefore, we conclude that it is important to distinguish between sexual indifference (i.e., the absence of attractivity) towards relatives in daily social interactions and sexual aversion specific to a sexual context.