Masturbation has long been considered a normal sexual behavior for children, and now the first nationally representative study of the practice finds — er, confirms — that teen boys, more so than girls, do it early and often.

Masturbation is no laughing matter, argues lead author Dr. Cynthia Robbins, from the pediatrics department at Indiana University in Indianapolis (IU). It remains highly stigmatized and receives little serious attention, but her research shows that it can also influence teens in other aspects of sexuality. Teens who masturbate, for example, also seem to be more likely to have sex with a partner and to practice safe sex, according to the research, which was published online this month in the Archives of Pediatrics and Adolescent Medicine.

“It is important to let adolescents know about masturbation because they may receive either no information or mixed messages on masturbation, yet it is a major way adolescents express sexuality,” Robbins wrote in an e-mail.

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Robbins looked at 2009 data from 800 teens who participated in the National Survey of Sexual Health and Behavior (NSSHB). The adolescents ranged in age from 14 — by which time masturbation prevalence is pretty high — to 17. Teens (and their parents) were asked how frequently they had masturbated during the previous three months, the previous year and in general. They also responded to questions about condom use and if they masturbated alone or with a partner.

Researchers found that boys — but not girls — who masturbated appeared more likely to use condoms during intercourse.

Boys took more pleasure in self-pleasure: half said they masturbated at least twice a week, but only 23% of girls reported the same frequency. While fewer than half of girls reported ever masturbating, the survey found that close to three-quarters of boys said they did.

As children got older, they appeared more likely to masturbate. Just 63% of younger boys of reported masturbating at least once, but that figure increased to 80% among 17-year-olds. For girls, the percentage rose with age from 43% to 58%.

For boys and girls, masturbation was linked with an increased likelihood of oral sex and intercourse. For girls alone, it was also associated with a greater tendency for mutual masturbation and anal intercourse.

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That girls report less masturbation than boys may not necessarily reflect reality; instead, it could have more to do with societal stigma surrounding girls and masturbation. Researchers didn't attempt to explain the discrepancies in this study.

But Robbins calls masturbation a “fundamental component” of teen sexuality that's worthy of a deeper look. Stop snickering.

“In order to fully understand sexuality during adolescence, masturbation's role needs to be acknowledged and studied further,” she writes.

Bonnie Rochman is a reporter at TIME. Find her on Twitter at @brochman. You can also continue the discussion on TIME's Facebook page and on Twitter at @TIME.