Is there actually a correlation between emotional trauma and homosexuality
The widely accepted answer to this question is that homosexuality is not a choice but science has no concrete answer as to exactly why people are homosexual, heterosexual, or bisexual (or any other sexual orientations that one may identify with). 

The Wikipedia page, Homosexuality, offers many great references and indicates that science has not definitive answer for what the 'cause' of homosexuality, only that it may be an interplay between generics, hormones, and environment.