Male victims of sex crimes are twice as likely to report them as female victims, according to a new poll.
The survey found 16% of women and 8% of men had suffered sex attacks.
Of those, half the men reported the attack to police, compared with only a quarter of the women.
The results show a change in traditional behaviour in men, who tend to keep silent about rapes and indecent assaults.
Michael May of Survivors UK, which supports male victims, said: "There is a stigma attached to male sexual assault. Very few of the men we've seen in our 26-year history have reported sex assault or rape to police."
Javed Khan, chief executive of Victim Support, said: "It takes real courage for a victim of sexual abuse to come forward and report these distressing experiences. We understand it can be a difficult decision whether to report these types of crimes to the police, but urge anyone who has been affected by sexual abuse to seek support."
The poll of 1,561 women and 1,419 men by ITV's This Morning also found that one in three people know someone who has had their drink spiked.
Nearly two-thirds think celebrities "get off more lightly" in court.
Almost half say sentences for drug possession are not tough enough and 54% want the return of the death penalty. One in three say they should be told where paedophiles live. And nearly three-quarters believe prisoners get too many luxuries.
About 1,000 people are convicted of rape each year out of an average 3,000 cases brought, according to figures from the Ministry of Justice, the Home Office and the Office for National Statistics.