The one problem with big data is that it removes the human element – and dating is very much about human connection. I think the attraction to 20 year olds is in large part biological.But the same way I try to lay out best practices for dating and relationships while allowing for many exceptions to the rules, I think we’d all be well served to pay attention to how people really act when no one’s looking instead of taking their word for it. Men are attracted to women who are at their most fertile.Because they started off dating long-distance (Ryan was living in Colorado at the time), it was understood that they would not be exclusive: They initiated a policy Leah describes as “don’t ask, don’t tell.” But when Ryan moved to New York and began living with Leah a year and a half later, he assumed they would transition immediately into monogamy.

In his book, “Dataclysm,” he points out that who we want to be and who we really are can be two very different things.

Data reveals truths that we might not want to say out loud.

Or, more specifically, that going outside the partnership for sex does not necessitate a forfeiture of it.

“I was at a practice where we would meet every week, six to eight therapists in a room for teaching purposes and to bring up new things coming into therapy that weren’t there before,” says Lair Torrent, a New York-based marriage and family therapist.

This generation is radically rethinking straight sex and marriage, but at what cost?

In Part One of a two-part series, Rolling Stone goes under the covers in search of new approaches to intimacy, commitment and hooking up.

Of course, when you flip the data around and look at what age men find women most physically appealing, you get an appalling answer. It’s shocking to see on paper, but not so surprising if you’ve ever talked to an actual man, read a men’s magazine or looked at porn intended for men.

Instead of the female curve, which suggests that 34-year-old women like 34-year-old men, men find 20 year-old women most physically appealing, no matter how old they were. This doesn’t mean that 40 year old men want to MARRY that 20 year old woman, only that they find her the most physically appealing.

By the end of their dinner at a small Italian restaurant in New York’s West Village, Leah is getting antsy to part ways with her boyfriend Ryan, so that she can go meet up with her boyfriend Jim.