Thanks for the link to Satinover's summary. I think one of the best examples of associated traits that may be heritable but don't determine behavior were: dexterity, height, high metabolism, muscle growth, etc. All of which, when combined, may make for a tall, athletic person. If this person is born in New York City, he may become a basketball player. But if he is born in Brussels, the likelihood will be much less that he will become a basketball player, or ever even consider being one. So the traits MAY have been heritable, and when you put them together in one person, they MAY make for a better basketball player, but environmental influence still plays a major and determinant factor.
I am a believer in temperament (sometimes called personality) and that our temperament traits are heritable. I think different personalities become apparent very early and I believe it has a genetic component. Boys who are "sensitive, intelligent, have a heightened awareness of aesthetics, etc." are not necessarily going to be attracted to men. However, these boys are more likely to be bullied and mistreated because they manifest these traits. If such a boy has a father, the father may reject him. If such a boy is raised by a single mother (as is increasingly the case), he may yearn for attention and love from a male. If such a boy is molested by a male, he may associate sexual contact with men as a form of love and attention.
Before you know it, you have a young man who swears he has "been gay" for as long as he could remember, because when he was 3 years old he already had a sense of taste and was into fashion "just like girls are".
Excellent and accurate summary of exactly how it could happen. Thanks.