Does familiarity necessarily lead to erotic indifference and incest avoidance because inbreeding lowers reproductive fitness?

Incest: the psychological problem and the biological contradiction

We have yet to map an "inbreeding avoider" gene or design a psychological test that can accurately diagnose incest transgressors. Until those events occur, sociobiology, nursing, and psychology must explain phenomena, such as the incest taboo, with a theoretical language of supposition. It is in this light that the etiology of taboo is analyzed. This article proposes that a propensity for sexual selection originates in the gene system, and what becomes taboo is acquired through the learning that accompanies the experiences of the individual and culture when sexual selection occurs. Influences of the genetic system and psychological culture on the existence of a taboo are contrasted. The conclusion posits an eclectic taboo hypothesis, derived from the congruencies found in the literature, and suggests how this hypothesis can guide nursing interventions with incestual families.