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Genetic sexual attraction is a concept in which a strong sexual attraction may develop between close blood relatives who first meet as adults. There is no direct evidence for "genetic attraction" being an actual phenomenon and the hypothesis has been criticized as pseudoscience.


The term was coined in the US in the late 1980s by Barbara Gonyo, the founder of Truth Seekers In Adoption, a Chicago-based support group for adoptees and their new-found relatives.[1] She developed sexual feelings for her son when she met him after he was adopted away, but he did not want to be part of any such contact.[2]

People tend to select mates who are like themselves.[3] This holds for both physical appearance and mental traits. People commonly rank faces similar to their own as more attractive, trustworthy, etc. than average.[4] However, Bereczkei (2004) attributes this in part to childhood imprinting on the opposite-sex parent. The study also reported a correlation of 0.233 for extraversion and 0.235 for inconsistency (using Eysenck's Personality Inventory). A review of many previous studies found these numbers to be quite common.[3]

Because many traits are at least partially determined by genetics, genetic sexual attraction is presumed according to the hypothesis to occur as a consequence of genetic relatives meeting as adults, typically as a consequence of adoption. However this is a very rare consequence of adoptive reunions.[5]

Incest is extremely rare between people raised together in early childhood due to a reverse sexual imprinting known as the Westermarck effect, which desensitizes them to later close sexual attraction. It is hypothesized that this effect evolved to prevent inbreeding.[6][7]

Although reported frequently as anecdote in the field of psychology,[8][9][10] there are no studies showing that people are sexually attracted to those genetically similar to them. Studies of MHC genes show that unrelated people are less attracted to those genetically similar to them.[11][12] However, in mice, this lack of attraction can be reversed by adoption.[13] Whilst it has been documented that sexual attraction can occur between related individuals in some cases,[10] it is not clear that calling this attraction GSA is appropriate.[2]

Critics of the hypothesis have called it pseudoscience.[2] Amanda Marcotte of Salon has stated that the term is nothing but an attempt at sounding scientific while trying to minimize the taboo of incest. She also expressed that many news outlets have handled reports of the subject poorly by repeating what the defenders of the hypothesis have said as opposed to actually looking into the research on the supposed phenomenon. She states that most of the publications which have chosen to run stories of couples speaking about "genetic sexual attraction" are not legitimate news sources and that one of the blogs which were written by a woman in an incestuous relationship simply reads like a story of a young girl who's been groomed by her father.[2]


  1. ^ Kirsta, Alix (17 May 2003). "Genetic sexual attraction". The Guardian.
  2. ^ a b c d "Debunking genetic sexual attraction: Incest by any other name is still incest". Salon. 16 August 2016. Retrieved 28 September 2018.
  3. ^ a b Watson, David; Klohnen, Eva C.; Casillas, Alex; Nus Simms, Ericka; Haig, Jeffrey; Berry, Diane S. (1 October 2004). "Match Makers and Deal Breakers: Analyses of Assortative Mating in Newlywed Couples". Journal of Personality. 72 (5): 1029–1068. CiteSeerX doi:10.1111/j.0022-3506.2004.00289.x. PMID 15335336.
  4. ^ Penton-Voak, I.S.; et al. (Spring 1999). "Computer graphic studies of the role of facial similarity in judgements of attractiveness" (PDF). Current Psychology: Developmental, Learning, Personality, Social. 18 (1): 104–117. CiteSeerX doi:10.1007/s12144-999-1020-4.
  5. ^ Bob McKeown; Aziza Sindhu (7 May 2009). "Part 2: Genetic Sexual Attraction – Part One". The Current. CBC Radio.
  6. ^ Lieberman, Debra; Tooby, John; Cosmides, Leda (2007). "The architecture of human kin detection". Nature. 445 (7129): 727–731. Bibcode:2007Natur.445..727L. doi:10.1038/nature05510. PMC 3581061. PMID 17301784.
  7. ^ Fessler, Daniel M.T.; Navarrete, C.David (2004). "Third-party attitudes toward sibling incest". Evolution and Human Behavior. 25 (5): 277–294. doi:10.1016/j.evolhumbehav.2004.05.004.
  8. ^ Paul, Robert A. (1 December 2010). "Incest Avoidance: Oedipal and Preoedipal, Natural and Cultural". Journal of the American Psychoanalytic Association. 58 (6): 1087–1112. doi:10.1177/0003065110395759. ISSN 0003-0651. PMID 21364180.
  9. ^ M., Childs, Robert (1998). Genetic sexual attraction : healing and danger in the reunions of adoptees and their birth families. OCLC 124077946.
  10. ^ a b Greenberg, Maurice; Littlewood, Roland (March 1995). "Post-adoption incest and phenotypic matching: Experience, personal meanings and biosocial implications". British Journal of Medical Psychology. 68 (1): 29–44. doi:10.1111/j.2044-8341.1995.tb01811.x. ISSN 0007-1129.
  11. ^ Sample, Ian (24 May 2009). "Gene research finds opposites do attract". The Guardian. Retrieved 23 October 2018.
  12. ^ Grammer, Karl; Fink, Bernhard; Neave, Nick (1 February 2005). "Human pheromones and sexual attraction". European Journal of Obstetrics & Gynecology and Reproductive Biology. 118 (2): 135–142. doi:10.1016/j.ejogrb.2004.08.010. ISSN 0301-2115. PMID 15653193.
  13. ^ Penn, Dustin; Potts, Wayne (22 July 1998). "MHC–disassortative mating preferences reversed by cross–fostering". Proceedings of the Royal Society of London B: Biological Sciences. 265 (1403): 1299–1306. doi:10.1098/rspb.1998.0433. ISSN 0962-8452. PMC 1689202. PMID 9718737.