Some or all of these factors may contribute to someone embracing homosexuality:
1) poor parent/child relationship or missing parent
2) lack of childhood bonding with same gender parent
3) child sexually molested by same sex adult (statistically, homosexuals are far more likely to molest children than heterosexuals are)
4) boy with effeminate characteristics or girl who looks and/or acts somewhat masculine is teased as if homosexual, which becomes a self-fulfilling prophecy--"Maybe they're right"
5) child feels different for these reasons, then finds commonality in the homosexual culture through internet site or school peers or other group--"I must be gay"
6) many adults--especially women--who have never been attracted to the same sex decide to embrace that orientation for a variety of reasons
But No One Has Ever Been "Born This Way."
Additional information:
http://www.frc.org/get.cfm?i=Is01B1
http://www.rossolson.org/homosexuality/causes_narth.html
http://www.narth.com/docs/coll-harren.html
http://ankerberg.org/Articles/_PDFArchives/streams-of-life/SL2W0803.pdf
