“If the millennials do something very different as they get older, say they decide they’re going to have a lot of sexual partners in their 40s, then yes this number could end up looking different in 10 years,” says Jean Twenge, author of Generation Me and one of the original authors of the study. “But that would be unusual.” The study found that millennials were likely to have had an average of about 8 partners, while Boomers were more likely to have had 10 or 11.

But if millennials are going to keep sowing their wild oats into middle age, another recent study suggests they’ll need to up their game: less than 7% of 20-somethings have sex 2-5 times per week, according to data from online dating service Match, and 49% of people in their 20s have not had sex at all in the past year.

Even more shocking? The study says one in three 20-somethings have never had sex at all. “You’d think they’d be focused on sleeping around, but really what they’re focused on is getting ahead,” explains Dr. Helen Fisher, a biological anthropologist at Rutgers University and Chief Scientific Advisor for Match. “In their 20s I think they’re working very hard. There’s something to be said for the fact that they may be taking relationships and commitment more seriously.”