Additional ‘gay gene’ studies  can be found here.

Hamer Study:

Dean Hamer, et al., of the National Cancer Institute, “A Linkage between DNA markers on the X Chromosome and Male Sexual Orientation,” reported in Science magazine, July 1993.  The media reported that the “gay gene” was discovered as a result of this study.  The researchers studied 40 pairs of homosexual brothers and suggested that some cases of homosexuality are linked to a specific region on the X chromosome (Xq28) inherited from the mother to her homosexual son.  Thirty-three pairs of brothers shared the same pattern variation in the tip of one arm of the chromosome.  Hamer estimated that the sequence of the given genetic markers on Xq28 is linked to homosexuality in 64% of the brothers.

  • There was no control group.  This poor scientific methodology.  Hamer and associates failed to test the heterosexual brothers.  What if the heterosexual brothers had the same genetic markers?  Source: Cohen, Richard (2000).  Coming Out Straight: Understanding and Healing Homosexuality, Chapter 2.
  • One of Hamer’s fellow research assistants brought him up on charges, saying that he withheld some of the findings that invalidated his study.  The National Cancer Institute is investigating Hamer. (To date, they have not released the results of this investigation.) Source: (1995) NIH “Gay Gene” Study Questioned. Science 268:1841.
  • A Canadian research team using a similar experimental design (This study used 52 pairs of gay siblings from 48 families.  Hamer’s research used 40 homosexual brother pairs.) was unable to duplicate the findings of Hamer’s study.  Source: Rice, G., Anderson, C., Risch, N., Ebers, G. (1995) Male Homosexuality: Absence of Linkage to Microsatelite Markers on the X Chromosome in a Canadian Study.  Presented at the 21st Annual Meeting of Sex Research.  Provincetown, MA.
  • Hamer states, “These genes do not cause people to become homosexuals…ultimately, it is the environment that determines how these genes will express themselves.”  Source: Time, April 27, 1998, p. 60-61.

CHRONOLOGY OF EVENTS CONCERNING HAMER STUDY:

1993    Hamer announces there is a “gay gene,” as reported in Science magazine.

1993    November 21, PFLAG meeting in Maryland: According to an eyewitness account by Peter LeBarbera, Dean Hamer told the audience that he was pleased with media coverage.

Hamer said, “If you tell the press what to write about a scientific study, they’ll write it.”  He added that he told reporters that his study’s findings show that sexual orientation is like being “left-handed,” and that they obliged him: “That’s what I told them to say, and they said it.” Source: Peter L. LaBarbera, “’Born Gay’ Researcher Explodes at LR,” Lambda Report on Homosexuality, December-January 1994, p. 17

1994    The National Cancer Institute investigates Hamer.

1998    Hamer acknowledges that there is no “gay gene.”

PFLAG has created a booklet, entitled “Why Ask Why?,” addressing the research on homosexuality and biology.  The pamphlet says: To date, no researcher has claimed that genes can determine sexual orientation.  At best, researchers believe that there may be a genetic component.  No human behavior, let alone sexual behavior, has been connected to genetic markers to date…sexuality, like every other behavior, is undoubtedly influenced by both biological and societal factors.