Editing Sexual fluidity (section)

==Biology and stability==

Conversion therapy (attempts to change sexual orientation) is rarely successful. In Maccio's (2011) review of sexual reorientation therapy attempts, she lists two studies that claim to have successfully converted [[gay men]] and lesbians to heterosexuals and four that demonstrate the contrary. She sought to settle the debate using a sample that was not recruited from religious organizations. The study consisted of 37 former conversion therapy participants (62.2% were male) from various cultural and religious backgrounds who currently or previously identified as lesbian, gay, or bisexual. The results indicated that there were no statistically significant shifts in sexual orientation from pre- to post-treatment. In follow-up sessions, the few changes in sexual orientation that did occur following therapy did not last. This study stands as support for the biological origin of sexual orientation, but the largely male sample population confounds the findings.<ref>Maccio, E.M. (2011). Self-reported sexual orientation and identity before and after sexual reorientation therapy. Journal of Gay and Lesbian Mental Health, 15. 242-259.</ref>

Further support for the biological origin of sexual orientation is that [[gender atypical behavior]] in childhood (e.g., a young boy playing with dolls) appears to predict homosexuality in adulthood (see [[childhood gender nonconformity]]). A longitudinal study by Drummond et al. (2008) looked at young girls with [[gender dysphoria]] (a significant example of gender atypical behavior) and found that the majority of these girls grew up to identify as bisexual or lesbian.<ref>{{cite journal | last1 = Drummond | first1 = K.D. | last2 = Bradley | first2 = S.J. | last3 = Peterson-Badali | first3 = M. | last4 = Zucker | first4 = K.J. | year = 2008 | title = A follow-up study of girls with gender identity disorder | journal = Developmental Psychology | volume = 44 | issue = 1| pages = 34–45 | doi=10.1037/0012-1649.44.1.34| pmid = 18194003 }}</ref> Many retrospective studies looking at childhood behavior are criticized for potential memory errors;<ref>{{cite journal | last1 = Rieger | first1 = G. | last2 = Linsenmeier | first2 = J.A.W. | last3 = Gygax | first3 = L. | last4 = Bailey | first4 = J.M. | year = 2008 | title = Sexual orientation and childhood gender nonconformity: evidence from home videos | journal = Developmental Psychology | volume = 44 | issue = 1| pages = 46–58 | doi=10.1037/0012-1649.44.1.46 | pmid=18194004}}</ref> so a study by Rieger, Linsenmeier, Gygax, & Bailey (2008) used home videos to investigate the relationship between childhood behaviors and adult sexual orientation. The results of this study support biological causation, but an understanding of how cultural assumptions about sexuality can affect sexual identity formation is also considered.<ref>{{cite journal | last1 = Hegarty | first1 = P. | display-authors = et al. | year = 2009 | title = Towards an LGBT-informed paradigm for children who break gender norms: comment on Drummond ''et al.'' (2008) and Rieger ''et al.'' (2008) | url = http://epubs.surrey.ac.uk/72257/5/2009%20Toward%20an%20LGBT%20affirmative%20infromed%20paradigm%20for%20children.pdf| journal = Developmental Psychology | volume = 45 | issue = 4| pages = 895–900 | doi=10.1037/a0016163| pmid = 19586166 }}</ref>

There is strong evidence for a relationship between [[fraternal birth order and male sexual orientation]], and there has been biological research done to investigate potential biological determinants of sexual orientation in men and women. One theory is the second to fourth finger ratio (2D:4D) theory. Some studies have discovered that heterosexual women had higher 2D:4D ratios than did lesbian women but the difference was not found between heterosexual and gay men.<ref>{{cite journal | last1 = Grimbos | first1 = T. | last2 = Zucker | first2 = K.J. | last3 = Dawood | first3 = K. | last4 = Burriss | first4 = R.P. | last5 = Puts | first5 = D.A. | year = 2010 | title = Sexual orientation and the second to fourth finger length ratio: a meta-analysis in men and women | url = https://semanticscholar.org/paper/e9d1dec17a9aab305fc44e26f73af0bdd73983b5| journal = Behavioral Neuroscience | volume = 124 | issue = 2| pages = 278–287 | doi=10.1037/a0018764 | pmid=20364887| s2cid = 2777884 }}</ref> Similarly, a study has shown that homosexual men have a sexually dimorphic nucleus in the anterior hypothalamus that is the size of females’.<ref>LeVay 1991 as cited in {{cite journal | last1 = Miller | first1 = E.M. | year = 2000 | title = Homosexuality, birth order, and evolution: toward an equilibrium reproductive economics of homosexuality | doi = 10.1023/a:1001836320541 | pmid = 10763427 | journal = Archives of Sexual Behavior | volume = 29 | issue = 1| pages = 1–34 | s2cid = 28241162 }}</ref> Twin and family studies have also found a genetic influence.<ref name=Bailey/>