on 20 April 2008
At least 95% of youth will grow up heterosexual anyway - that's the way it's always been, and always will be. Can you prevent the rest from growing up homosexual (or bisexual)? The trouble is that it's impossible to demonstrate with anything even approaching probability that you have ever succeeded in preventing anyone from growing up homosexual who would otherwise have done so; all that you can sometimes prove is that you haven't.
The most extensively documented case of an attempt to "head off" homosexuality in a boy - which was undertaken because he was gender-nonconformist as an infant - was that of the boy known in the literature variously as Craig, Kraig or Kyle. The good news is that the attempt was a failure; the bad news is that the "treatment" that he was given did him serious psychological harm.* You can read about it in Chapter 4 of Simon Levay's book "Queer Science".
Don't bother with this book: you'll just find a recycling of the tired old anti-gay myths about the alleged causes of homosexuality. If you are the parent of a gay child, or if you are concerned about the possibility that your child may turn out to be gay, then I would advise you to take to heart what a well-known Irish priest said: "You must be very special parents to know and to have a gay son. God does not give gay children to everybody. What a unique privilege for you."
* I've periodically wondered what happened to poor Craig/Kraig/Kyle, hoping that his life had not been totally wrecked, that he had somehow succeeded in recovering from the psychological and spiritual abuse that was inflicted on him, and that he was now perhaps settled in a loving gay relationship. Alas! This was not to be. Kirk (we now know his real name) took his own life at the age of 38. His sister has commented, "What I now think is, I don't know how he made it that long." May he rest in peace.