What is Genetic Sexual Attraction?

Genetic sexual attraction is a phenomenon of sexual attraction between biological family members that typically occurs after close relatives, such as siblings or parents and children, are reunited after a long period of separation — typically separation from birth. It is important to note, however, that the name can be misleading, because the phenomenon often does not lead to actual sexual contact between family members. The name was coined by Barbara Gonyo in the 1980s in an attempt to separate the issue from incest, because incest is typically considered synonymous with abuse. Genetic sexual attraction, on the other hand, occurs between consenting adults who know nothing of their familial ties prior to meeting and, in some cases, have no idea they are related even when they meet. This phenomenon is believed to be caused by several factors, most notably basic human attraction and a lack of the bonding with family members that typically occurs in the early stages of one’s life.

It has long been held that human beings are most attracted to those who have similar physical attributes. When siblings are raised together, or when biological parents raise their biological children, something known as the Westermarck effect occurs. This is believed to be a biological evolution that prevents inbreeding and effectively turns off the sexual attraction part of a person’s brain when it comes to people with whom they are raised and consider family. When children are separated at birth, the Westermarck effect does not occur. The lack of this imprinting couples with the tendency for humans to be attracted to those who resemble them to become what is considered one of the leading causes of genetic sexual attraction.

The close bonding with relatives that occurs during the infant and toddler years, especially between a mother and her child, is another reason for genetic sexual attraction. After a long separation, family members report feeling an immediate need to make this bond, which often translates into feelings of attraction and a strong and almost indescribable need to feel close to the other person. The closeness that comes from snuggling, kissing and comforting an infant is one of the most important biological needs of humans, according to many psychologists, and the lack of this closeness can turn into sexual attraction. This need is what makes this phenomenon most likely to affect mothers and their children.

The social stigma attached to incestuous relationships and, therefore, the lack of reporting means researchers have a difficult time placing a number on how many people experience genetic sexual attraction. Despite this, many adoption agencies and post adoption support groups believe this phenomenon affects at least 50 percent of adopted people who are reunited with their biological family.