Genetic Sexual Attraction: Urban legend or ticking time bomb?

Recent headlines announcing a British couple that discovered they were long-lost twins separated at birth (Parted-at-birth twins ‘married’, BBC, January 11, 2008), has born a new interest into the need for people to know their biological parents and subsequent siblings.  A friend of the couple told the House of Lords that the twins felt an “inevitable attraction”.  While it is not stated publicly it is assumed that this could only be a case of genetic sexual attraction.

So what exactly is genetic sexual attraction (GSA), or for better phrase simply genetic attraction (as it can be sexual or not)?  The founder of Truth Seekers in Adoption (a Chicago based adoption support group for adoptees who have recently found their biological relatives), Barbra Gonyo first used the term in the late 1980s.  It has been shown most commonly in the adoption community among adult adoptees meeting their birth parents or siblings later in life, where upon meeting there is an intense and sometimes sexual attraction to the parents, child, or sibling.  According to The Guardian (Genetic Sexual Attraction, May 17, 2003), some adoption groups estimate that some aspects of GSA occur in close to 50% of reunion cases, however due to the taboos that surround the phenomenon, the actual rate of occurrence is impossible to determine.  

Gonyo suggests that it stems for the lack of bonding that normally takes place between an infant and its mother or between siblings who were raised together.  Gonyo stated that since she became director of Truth Seekers she sees people struggling with GSA constantly. 

"Often, the attraction isn't sexual, but it's still frightening and alien, and therefore perceived as abnormal and sinful. One woman told me that she and her birth mother, soon after they met, slept together in the nude: there was no sex, only a strong need to be close as parent and child. Grown men tell me they've sat in their mother's lap, just being rocked and held. One man talked about his need to be sexual with his newly found brother, but not being homosexual they shared a woman instead" (Genetic Sexual Attraction, The Guardian, May 17, 2003).

Research on a type of reverse sexual imprinting called the ‘westermarck effect’ sheds light on the underlying biological urges associated with GSA.  According to Mark Schneider, the westermarck effect is a sexual inhibition found in individuals raised together that he argues is mediated by the olfactory system.  “Evidence suggests aversions develop during an early sensitizing period, attach to persons as much as to their scents, and are more powerful among females than among males.”  (Olfactory sexual inhibition and the westermarck effect, Human Nature, Vol. 11, March 2000, pp. 65-91).

This reverse sexual imprinting has been observed in several cultural systems such as the Israeli Kibbutz (communal living arrangements where children were raised in like-aged peer groups), and the Chinese Shim-pua marriage customs, where young girls were adopted by their future husband’s parents and raised as a ‘little daughter-in-law’.  In both of these cases the children later in life rejected marriage with one another (either not looking for mates in their peer group, or refusing to marry their fiancé), despite their parents hopes. 

Another well known case of GSA, was that of Gary Klahr and Micka Zeman who had a six-month relationship in 1979, and in 1998 discovered that they were both two of 13 children born to a couple and nine of those children were adopted to families in the area.  After realizing that they had sex with one another long before knowing they were siblings they felt sick, but knew there was no sense in feeling guilty, as they had not known and it could not have been prevented at the time.  Yet the connection that they felt was no doubt an unconscious biological attraction. 

“[I]f you understand that nine out of 13 children from the biological family were adopted out to different families, with different names and different religions, within a 15-mile radius of the hospital where we were born, then something like this was bound to happen. I [Gary] never had an idea, until 1998, that I was adopted: how could we have known that we were brother and sister?” (The Guardian, May 17, 2003).  

So now lets jump to the 21^st century, the age of test-tube babies and assisted reproduction.  The infertility industry states in response to the possibility of siblings meeting and falling in love, that the chance of that is so rare that it does not justify banning anonymity.  However, if we look at the fact that sperm bank regulations recommend that “In a population of 800,000 limiting a single donor to no more than 25 births would avoid an increased risk…” (Fertility and Sterility supplement, June 2002)  With that being said, lets take the city of New York for example.  With an estimated 2006 population of 19,306,183 (New York Quick Facts, US Census Bureau, 2008), that would mean a single donor could have 603 offspring just in the NYC city limits – not to mention across the country!!!!  These offspring would more than likely be of similar ages and races, and if we take into account that probably 80-90% of donor offspring have no idea they’re donor conceived, and now the idea of genetic attraction which could unconsciously bring two offspring together – this is a time bomb waiting to happen.

I think it’s about time that people begin to realize that this is an actual reality and that the consequences are beyond what we can imagine.  We’re not just worried about half-siblings meeting, but what about cousins and other degrees of consanguinity??  And while birth defects due to increased degrees of consanguinity are still low, take a look at the risks on a larger scale.

British born Pakistani’s (55% marry a first cousin) are 13 times more likely to have a child with a genetic disorder, or one in ten Pakistani children of first cousin marriages die in infancy or have a severe disability.  While Pakistani’s only account for 3% of the UK births, they produce “just under a third” of all British children with genetic diseases (J. Rowlatt, The risks of cousin marriage, BBC, November 16, 2005).

While GSA is still a highly controversial subject and hotly debated whether it actually exists and what the repercussions should be (treated as a moral/legal issue or not), it needs to come to the attention of those in the donor conception community as a risk that should not be taken lightly.  If anything, disclose your child’s means of conception so that in the future at least that knowledge is there!