Even more shockingly, over seven percent were under the age of 10 when they first came into contact with internet porn. By the age of 14, the majority - 60 percent - of young people had seen porn online.
Two-thirds of the young people surveyed said that their first contact with porn was unintentional, accessed accidentally while browsing online. But 87 percent of males and 52 percent of females told researchers that they have deliberately searched pornographic images and videos at least occasionally.
The results of the survey were sharply polarised by gender. While 20 percent of the young women questioned reported never having accessed online porn, only four percent of males could say the same.
And while half of young male porn users admitted looking at porn at least once a week, only 10 percent of female porn users accessed adult material as frequently.
The research was commissioned by the BBC for a new documentary entitled Porn: What's the Harm?, to be broadcast this evening.
The survey found that half of the one thousand 16-21-year-olds asked about their experiences with porn reported that viewing adult videos online had influenced their perception of sex.
Worryingly, they found that pornography seem to be affecting young men in particular, with many telling researchers that seeing porn at a young age had influenced their views of female sex partners, whom they expected to act like porn stars.
The documentary's presenter, Jameela Jamil, explained why she thought the findings were a cause of concern. "I worry about the new generation of men whose first real introduction to sex is what they see on their laptop," she said. "They think we are supposed to look, sound and move like that."
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