One in five US adolescents has sex before turning 15

According to the report, many of those who lose their virginity before age 15 have had sex sporadically.

One of the studies found that 4 in 10 of the sexually experienced young people had had sex in the 18 months preceding the survey, and another found that half of those who were no longer virgins had engaged in intercourse twice or less in the last year.

The data in the report comes from three federally financed surveys of young people and four smaller data sets.