A Good Poop

Blood and sexual orientation

Ellis L, Ficek C, Burke D, Das S. Eye color, hair color, blood type, and the rhesus factor: exploring possible genetic links to sexual orientation. Arch Sex Behav. 2008 Feb;37(1):145-9.

Based on a sample of 2000+ college students and people found in internet chat rooms, the authors of this paper found that gay men and lesbians exhibited low and high incidences, respectively, of A blood type compared to heterosexuals (p < 0.05). Additionally, they found that a unusually high proportion of homosexuals of both sexes were Rh- (i.e. had no Rhesus D antigen on their red cells) compared to heterosexuals (p < 0.06). Blood type and Rh factor were self-reported, and the internet chat room sampling sounds sort of sketchy. If the stats hold, since blood type and Rh factor are genetically determined, there might be some kind of genetic linkage thing going on with sexual orientation. Zip zap.


  1. #1 Joshua Zelinsky
    March 23, 2008

    Interesting, but there are a lot of other possible explanations. For example, blood-types vary to some extent by racial/ethnic groups. If certain groups are more willing to accept homosexuals then more people of those groups might be willing to identify as homosexual. I can think of at least two or three other hypotheses that might explain this data.

  2. #2 Libertarianchick
    March 23, 2008

    So does that mean that AB people are bi? It’s true in my case. 🙂

  3. #3 holycrap08
    March 25, 2008

    I’m a lesbian and I have been very curious about the genetic end of it. I’m B with RH- blood.

    But, like the above poster said…homosexuality isn’t widely accepted yet, so there is probably a very large group of closeted homosexuals that haven’t been accounted for yet.

  4. #4 Jinx
    August 22, 2008

    Haha! First off, I’m omnisexual. Or Bisexual.

    Most of my blood test could not determine my Rh factor! Some said positive, some said a weak negative. I guess it changed based on what flavor I was wanting that week, LOL!

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