From the New York Times:
Full article:
http://www.nytimes.com/2002/04/23/health/psychology/23BEHA.html (free registration required).
The researchers found that boys with high self-esteem were 2.4 times as likely to say they had had sex as the boys with low-self esteem. But girls with high self-esteem were three times as likely to report being virgins as the girls with low self-esteem.
[...]
The researchers said they could not be sure what the results meant, though they suggested that the study offered evidence that the double standard among girls and boys remained strong when it came to sex. When it came to ascertaining the degree of sexual activity, the researchers had nothing to go on but the word of the students being surveyed.
Full article:
http://www.nytimes.com/2002/04/23/health/psychology/23BEHA.html (free registration required).