Sexual strangulation, nearly always of women in heterosexual pornography, has long been a staple on free sites, those default sources of sex ed for teens. As with anything else, repeat exposure can render the once appalling appealing. It’s not uncommon for behaviors to be normalized in porn, move within a few years to mainstream media, then, in what may become a feedback loop, be adopted in the bedroom or the dorm room.

Choking, Dr. Herbenick said, seems to have made that first leap in a 2008 episode of HBO’s “Californication,” where it was still depicted as outré, then accelerated after the success of “Fifty Shades of Gray.” By 2019, when a high school girl was choked in the pilot of HBO’s “Euphoria,” it was standard fare. A young woman was choked in the opener of “The Idol” (again on HBO and also, like “Euphoria,” created by Sam Levinson; what’s with him?). Ali Wong plays the proclivity for laughs in a Netflix special, and it’s a punchline in Tina Fey’s new “Mean Girls.” The chorus of Jack Harlow’s “Lovin On Me,” which topped Billboard’s Hot 100 chart for six nonconsecutive weeks this winter and has been viewed over 99 million times on YouTube, starts with, “I’m vanilla baby, I’ll choke you, but I ain’t no killer, baby.” How-to articles abound on the internet, and social media algorithms feed young people (but typically not their unsuspecting parents) hundreds of #chokemedaddy memes along with memes that mock — even celebrate — the potential for hurting or killing female partners.

I’m not here to kink-shame (or anything-shame). And, anyway, many experienced BDSM practitioners discourage choking, believing it to be too dangerous. There are still relatively few studies on the subject, and most have been done by Dr. Herbenick and her colleagues. Reports among adolescents are now trickling out from the United Kingdom, Australia, Iceland, New Zealand and Italy.

Twenty years ago, sexual asphyxiation appears to have been unusual among any demographic, let alone young people who were new to sex and iffy at communication. That’s changed radically in a short time, with health consequences that parents, educators, medical professionals, sexual consent advocates and teens themselves urgently need to understand.

Sexual trends can spread quickly on campus and, to an extent, in every direction. But, at least among straight kids, I’ve sometimes noticed a pattern: Those that involve basic physical gratification — like receiving oral sex in hookups — tend to favor men. Those that might entail pain or submission, like choking, are generally more for women.