Researchers are saying millennials who delay sex are probably just waiting for the right time and the right relationship. They are responding to a new study that finds fewer Millennials than previous recent generations are likely to have had sex. While only six percent of Generation Xers aged 20- to 24-years-old said they remained virgins after they turned 18, the new study showed 15 percent of Millennials of the same age had not engaged in sex after reaching 18.

Debby Herbenick, Ph.D., Indiana University associate professor, says research shows women and men prefer sex within relationships. “Maybe both sexes are simply getting smarter about sex, listening to their gut instinct, and preferring instead to wait it out until they find a situation that works well for them,” she said in an interview with Glamour.

Herbenick, who is the author of Because It Feels Good: A Woman’s Guide to Sexual Pleasure and Satisfaction, did not work on the study of nearly 27,000 people from San Diego State University.

Other experts say the study may indicate women are exercising their power to refuse unwanted sex. “As people have gotten much more accepting of all sorts of forms of consensual sex, they’ve also gotten more picky about what constitutes consent,” said Stephanie Coontz, director of research at the Council on Contemporary Families. “We are far less accepting of pressured sex,” she said in a Washington Post interview.

And they say deliberating choosing when to have sex ultimately can lead to stronger relationships.

The reported finding of sexual inactivity belies the so-called “hookup culture” attributed to Millennials. More are not having sex at all, much less hooking up with multiple partners.

San Diego State University psychology professor Jean M. Twenge, who led the new study, said online dating apps may be making an unexpected impact. “Online dating apps should, in theory, help Millennials find sexual partners more easily,” she said. “However, technology may have the opposite effect if young people are spending so much time online that they interact less in person, and thus don’t have sex,” Twenge wrote.

She said she found those who participated in the study are making sexual choices that reflect their aversion to risky behavior. They have cut consumption of alcohol, and they are interested in “safe spaces” on campus. Reports of collegiate sex abuse may have contributed to their heightened awareness of personal safety, she said.

The researchers published their new study this week in the journal Archives of Sexual Behavior.