Stephen Gately of Boyzone chose the Sun as the platform from which to declare his homosexuality. An odd choice, you might think, until you learn that he was about to be outed anyway by the Sun's sister paper, the News Of The World.

Outing gays is food and drink to the tabloid press. If pop stars aren't available (think Elton John and George Michael) then there are always politicians - most recently in Britain, agriculture minister Nick Brown and Welsh minister Ron Davies.

Chastity Bono knows a lot about outing. Daughter of Sonny Bono and Cher, she was outed as a lesbian by an American tabloid barely a year after admitting her homosexuality to her parents. She was 20. "Instead of standing tall and feeling proud of who I was, I made the decision to hide from the media, pretend that I was not gay," she writes in Family Outing, subtitled: The guide to coming out for gays, lesbians and their parents.

The case histories which illustrate the problems confronting young gay people and their families are all versions of her own experience: child senses own difference and feels uncomfortable; child is taunted and teased by peers, then rejected by parents.

But homophobia (fear of homosexuality, not dislike, she points out) is not only commonplace among the world at large but among gays too, as they themselves are products of a homophobic society, she explains.

Those in the public eye often choose to keep their homosexuality hidden, fearing it could hurt their career if it became known. Though Chastity Bono herself used the same excuse - at the time of her outing she had just signed a recording contract for her band - she no longer believes this is the case.

"I think the problem goes back to that person's internalised homophobia. They themselves aren't really comfortable with who they are and therefore they are hiding it and keeping it a secret and using the `I'm-worried-about-my-career' as an excuse. But the bottom line is, as human beings in general, we don't hide something we're not ashamed of. We don't lie about certain things about ourselves that we don't find shameful."

Rooting out this homophobia - this fear of the unknown - is at the heart of Chastity Bono's crusade. "I don't know how it is in Ireland, but in America we have a three times higher suicide rate with gay youth than among straights, and the problem is the perception of how society perceives the gay community. In the United States when we had a serial killer Andrew Cullinan he was labelled the gay serial killer, the homicidal homosexual. You don't have people labelled the Jewish serial killer or the Italian serial killer.

"It's the way that gay people are presented. Of course there are extreme people in our culture, but there are extreme people within the hetero culture as well, yet they don't get portrayed constantly as being examples of that culture. The truth is that the everyday gay person is no different from the everyday straight person."

It is up to everyday gays to come out and dispel that fear of difference, Bono believes. "The more gay people come out, the more difficult it is to stereotype them. People who know someone that is gay are more likely to be more sensitive to our issues than somebody who doesn't. Somebody who doesn't know anyone who admits to being gay can believe the stereotype not knowing any better. When you know someone who is gay it makes it harder to see them in a negative light."

Chastity Bono's own outing sent her spiralling down the path of denial for many years. Those around her had all supported her decision to deny it - her girlfriend, her aunt and her mother. Once again, the rationale was that it would harm her burgeoning musical career. Not to mention, one suspects, her mother's.

While being the daughter of famous parents might help her now in getting media attention for her cause, when she was most vulnerable it made her a victim. She became a recluse, hating the gay community and hating herself. Understandably, she does not believe in "outing", except in the case of "closeted gay politicians voting against gay bills".

It is the only time in the interview when her anger shows through. Such behaviour is outrageous, she says. "A lot of people don't enter politics for noble reasons. There must be an incredible amount of internalised homophobia that somebody could be in a position to help create change and be so ashamed of themselves that not only will they not come out, but they will vote against something that will help gay people."

One of Chastity Bono's great sadnesses is that she was never reconciled with her father, Sonny, who was killed in a skiing accident in January 1998. Although supportive during the early days of her coming out, their ways parted when he became a Republican congressman and she took off as a gay activist. The nadir came when he sponsored the Defence of Marriage Act, which his daughter saw as a personal betrayal. She never had a chance to confront him because by then they were no longer talking.

Stories in Family Outing repeatedly centre on the difficulties parents have in understanding homosexual children. Accepting your children's sexuality is difficult even in a heterosexual context, yet the problems confronting a gay child are many times worse. "It's really important that parents help their kids cope with this as they would with any other problem," explains Bono.

Cher did not cope well. It has taken her nearly 10 years to come to terms with her daughter's homosexuality, from the shock and anger of finding her in bed with a girlfriend - and insisting on therapy - through where-did-I-go-wrong breast-beatings, to publicly supporting her daughter. It has brought them as close as mother and daughter can be, believes Chastity.

"Looking back on your childhood it is very easy to sit and bitch about a million different kind of things. I would have liked to have grown up in the ideal Brady bunch family way too, but guess what, that's not how life works."

Perceived difference creates fear, says Bono. But, she insists, the lives of gay people are no different from the lives of heterosexuals. "Most of the gay people I know are coupled in monogamous relationships. Most of the straight people I know are in monogamous relationships. Some have kids, some don't. The things that concern both of them are the same type of things: good job, nice house, someone to share your life with that you're compatible with and you love. That is the thing. There is no secret handshake. And that's an important thing to get across to people."

Family Outing, by Chastity Bono with Billie Fitzpatrick is published by Pan, at £6.99 in the UK