Are people who consider themselves homosexual born that way?

If they are not born this way then what factors in their life caused their personal life choices?


Sources
http://www.time.com/time/magazine/article/0,9171,973763,00.html
http://www.str.org/site/PageServer?pagename=PL_article_are_homosexuals_born_that_way
http://www.independent.co.uk/life-style/health-and-families/features/gay-born-this-way-2297039.html
http://www.freerepublic.com/focus/f-news/1300464/posts
http://www.boston.com/news/globe/magazine/articles/2005/08/14/what_makes_people_gay/
http://psychology.ucdavis.edu/rainbow/html/facts_mental_health.html
http://borngay.procon.org/view.answers.php?questionID=000018
http://www.time.com/time/magazine/article/0,9171,978923,00.html#ixzz1oeNyYTUv
http://www.freerepublic.com/focus/fr/724179/posts
http://www.newstatesman.com/life-and-society/2007/07/gay-living-ssa-choice-school
http://www.stevegershom.com/2010/12/a-dry-tree/
http://www.bio.davidson.edu/courses/genomics/2002/pierce/gaygene.htm
http://www.trueorigin.org/gaygene01.asp
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