I have always been slightly bemused by homophobia. Why would two adults (or 10) having consensual sex upset you? What's it to you? A new expose of one of the West's most rancidly anti-gay subcultures – hip-hop – offers the beginnings of an answer.

Hip-hop has long been the ultimate in fag-bashing, gay-trashing hate music. Listen to many albums and a list of homophobic howls will hit you: Eminem squeaking "Hate fags? The answer's yes!", or Masse saying "I be wastin' em. That's what you faggots get!" The music's mood was summarised in a 1992 Ice Cube hit: "True niggaz ain't gay."

This boom-boom-boom of homo-cidal hate has a crushing effect on gay kids. It sends out the message: you are so repulsive you should be killed. It's one of several reasons why gay teenagers are still – after all the amazing progress we have made – six times more likely to commit suicide than their straight siblings.

Why do they do it? Why do hip-hop artists – often the victims of bigotry themselves – incite this hatred? For 10 years, Terrence Dean was at the heart of the hip-hop scene as a producer at MTV and Warner Brothers. His life is as ghetto as any of the big name artists. His mother was a heroin-addicted, Aids-infected prostitute whose "clients" held Terrence hostage at gunpoint. His drunken grandmother raised him in the slums of Detroit, and he eventually ended up in prison. When he was released, he headed for Hollywood – and he was amazed to stumble into a gay underworld stocked with some of the biggest names in hip-hop.

I recently interviewed Dean for the gay magazine Attitude. He told me about a man – I don't believe in outing, so I won't give his name – who "has been named in the past as one of the biggest rappers of all time by MTV. He's always trashing gay men in his lyrics. But he is surrounded by a posse of transvestites," who he has sex with. Dean then runs through a list of hip-hop gays, each more famous and closeted than the last.

He explains: "When the rappers rap about the hatred they have of homosexuals, I know it's because many of them are struggling with their own sexuality. They hate what they are and in turn they spew their hatred toward men who are reflections of themselves."

Terence tried to live their life. He explains: "They had to see me with women. I talked the talk – cars, sports, women. One misstep would have been the end of my career. Hell, it would have been the end of my life." But it was a miserable, bitter existence, based on violent emotional repression. These homie-sexuals even convinced themselves they could have sex with men without being "gay" – a term they see as synonymous with being weak and womanly.

The claims made in Dean's autobiography, Hiding in Hip-Hop: On the Down-Low in the Entertainment Industry – From Music to Hollywood, have been taken seriously enough to rattle the whole industry. There is some scientific evidence to suggest that is right – and that his arguments apply much more widely, to homophobes in politics, religion and the wider world. Professor Henry Adams at the University of Georgia conducted a major study in the 1990s, where he took several groups of men who identified as heterosexual and expressed hostility to gays.

He then showed them gay porn – and some 80 per cent became aroused. He concluded that since "most homophobes demonstrate significant sexual arousal to homosexual erotic stimuli", anti-gay hatred is probably "a form of latent homosexuality."

Of course, not all of these hate-mongers are secretly gay. But we know from decades of sexual research that almost everyone – especially as a teenager – has a period when they have omnivorous sexual urges, with attraction to the "wrong" gender cropping up for a while. (Like most gay boys, I had a burst of heterosexual experiences when I was 15 and 16.) The question is: how do you deal with them? If you see this as an interesting, natural part of human experience, they will soon fade from your mind. If you see them as shameful or immoral, they will fester – and you will subconsciously project them outwards, on to the demonic, disgusting fags, who should be punished for tempting you.

How do we break through this? It has to start with honesty. Homosexuality is not some unnatural intrusion, wrought by demonic perverts, as the pre-modern religious texts so absurdly assert. It is an inevitable part of nature – birds do it, bees do it – and it is, fleetingly, part of the sexual development of most teenagers. If you are rivven with hate for homosexuals, the evidence suggests you have a psychological problem, based on denying part of yourself.

In short: homophobia? It's so gay.

j.hari@independent.co.uk