Despite the sex-orientated scenes we see on TV and in movies, and what we hear about a young generation obsessed with dating apps and casual hook ups, a new study shows that a large portion of the millennial generation is actually not having any sex at all.

The study was conducted by researchers Jean Twenge, Ryne Sherman and Brooke Wells from the University of San Diego and Wildener University in the US, and published in the Archives of Sexual Behaviour. Its findings read: ‘Millennials, especially those born in the 1990s, were significantly more likely to have no sexual partners as adults compared to Gen X’ers born in the 1960s.’

This was following previous research by Twenge and Sherman that found that those millennials who are having sex are still having less sex than previous generations.

So what are the reasons for this change in sexual behaviour? In an interview with New York Magazine, Twenge reflected, ‘I’m sure I’m not the only millennial who remembers that the concept of sex and fear of AIDS were tightly intertwined from the first time we really learned what the former was. Many of us grew up in the shadow of the peak of the AIDS epidemic.’

Another possible reason, she says, is that sex fits into the category of ‘adult’ activities that millennials have delayed. Studies have shown that more millenials are delaying moving out of their parents’ houses, getting married and being employed steady jobs.

‘People are marrying, having children, and settling into careers later. For GenX, that didn’t change when they started having sex. But for late Millennials and iGen, sex is now joining the later adulthood party. Sex has caught up to other adult milestones and is being delayed,’ says Twenge.

She also points out that in general there’s so much going on in the lives of millennials, and so many different things that define who they are like social media, technology and entertainment, that sex just isn’t as high on the list of activities to pursue anymore.