A majority of Americans, 77 percent, say celebrities like Britney Spears and Paris Hilton have too much influence over young girls, a new poll found.

However, Newsweek magazine says in its current cover story "The Girls Gone Wild Effect" overexposure to the sexy young celebrities may not be doing girls any harm. The Guttmacher Institute, a non-profit organization that specializes in sexual and reproductive health issues, reports that the average age for first sex among American girls is 17 — about the same as it’s been for 20 years, Newsweek reports.

The teenage pregnancy rate has dropped since 1990, as have the rates for drinking, smoking and drug use among teenage girls, Newsweek said, citing data from the University of Michigan.

Some girls want to emulate Spears’ fashion sense — but only up to a point, apparently. Suburban Chicago fifth-grade teacher Michelle Freitag told Newsweek her students "can’t understand why Britney would wear no underwear."