This raises more questions than it answers.
I think it a shame they made such a strong correlation with alcohol consumption. I would prefer not to think you need alcohol to enjoy sex.
It also seems they equate "sex" with "sexual intercourse". I wonder if the numbers change any when other forms of sexual activity are taken into account?
It would also help to break the numbers down by type of casual sex.
Sex engaged in by couples who have paired primarily for the sake of having an available sex partner.
Sex engaged in by people who are in relationships but may have some "old friends" they occasionally hook up with on the side.
Sex that happens primarily because one or both partners had consumed an excessive amount of alcohol.
Sex engaged in by people who actively pursue hook-ups especially with total strangers they expect never to see again.
In my personal experience, "casual" sex by which I would mean sex between 2 people who haven't expressed feelings for each other, happened because the female partner was randy and not timid about proposing sex. However in those cases I continued to "date" the person in question for some time after. Even the first time my wife and I did it, I believe a large motivation for her was that she hadn't had any for a while. I don't think she was actually "in love" with me yet, although it was mutually understood we would be an established couple going forward.
One explanation for millennials might be that, unlike people my age, they had enough casual encounters in high school that by the time they reached the age covered by this study, they were more particular. My son, who is now married to a woman he met when both were 20, had a lot of "casual" experiences in high school and by the time he was 20 he was probably more interested in something serious. Apart from my son and some of his friends, I have no real idea what goes on in high school these days or in the 2000s when my son was there.
Having said this, I can still say that in the 70s when I first became sexually active, there seemed to be a lower threshold for young women to have a sexual encounter when they happened to be in the mood and had just met a guy they fancied. It wasn't unusual for two college-age people to meet on a train and decide, after some conversation, to have sex when they got off. To state it simply, if a young woman met a guy she was attracted to, she didn't hesitate to have sex with him. A situation like this would have none of the cynicism one might associate with hooking up, more like "he's hot so I want to do him, why shouldn't I?". OTOH there was much less knowledge about sex then. It wasn't that unusual for a young woman to have never experienced orgasm because they didn't know how. My first girlfriend seemed to assume that orgasm is something that would eventually happen when you had intercourse, which in her case it did not. I mention her mostly though because I wanted to mention that, the one time I saw her after we were not longer a couple, she bragged to me that she had taken up the hobby of going to bars and picking guys up for sex. The reason I mention this is to emphasize how utterly unashamed she was of this activity. Whereas nowadays there seems to be a lot more shame attached to women having any sort of "casual" sex than there was back then, something I wish I better understood.
Last edited by MaxE on 04 Apr 2021, 12:26 pm, edited 1 time in total.