The average age at which people come out as gay, lesbian or bisexual has fallen steadily over the last four decades, according to the British gay rights group, Stonewall.
A poll for Stonewall of 1,500 people who were already out found that among the over-60s the average age they had come out was 37. But those in their 30s had come out at an average age of 21, and in the group aged 18 to 24 it was 17.
The survey, conducted via social networking sites, does not take account of the numbers of people who know they are gay or bisexual but have not come out. But Stonewall said it nonetheless revealed a pattern of people having the confidence to come out earlier.
Among the 33 respondents aged over 60, only five had come out under the age of 18. Several had only done so in the last 10 years.
Stonewall's deputy director of public affairs, Ruth Hunt, said: "People are coming out younger and younger. Everyone should come out when they feel ready and confident, but this is an encouraging trend and sends a positive message to anyone not yet out: you don't have to wait. Britain is a fairer country than it once was, and support is available to you."
She said the change was likely to be because young people today were given a lot more information about sexuality, and were more likely to see gay people in the public eye, on British TV programmes such as Emmerdale and EastEnders, with whom they could identify feelings they might be having.
"Older people may not have had the language for it, or necessarily seen other people they knew they were like," Hunt said.
"What we're seeing is an explosion of role models and people talking about being gay, so people are more able to associate what they're feeling with something they can see."
But she added that, although schools were now a better place to be for young people, some teachers and parents were still lagging behind in their willingness to discuss issues of sexuality.
"Young people are coming out in schools across Britain right now," Hunt said.
"As lesbian, gay and bisexual pupils become more visible than ever, it's essential schools make things better for them. Some teachers still think it's something private that shouldn't really be talked about, and some parents think that too. They aren't catching up at the same speed."
Stonewall is encouraging people to write to their MPs to ask if schools in their area are using the organisation's resources to tackle homophobic bullying.
Dalia Fleming, 21, who came out when she was 15, said that accessible role models made coming out easier for young people, although there were still not enough.
Changes including the introduction of civil partnerships and the end of Section 28 – which banned the "promotion" of homosexuality in schools – had also helped, she said.