It's a popular cultural trope these days that watching porn is making men, especially young men, sexually dysfunctional. "Porn is ruining the sex lives of an entire generation," trumpeted Business Insider a few years ago, citing a Psychology Today report relying on bit of neuro-nonsense to get the point across:

Today's users can force [their] release by watching porn in multiple windows, searching endlessly, fast-forwarding to the bits they find hottest, switching to live sex chat, viewing constant novelty, firing up their mirror neurons with video action and cam-2-cam, or escalating to extreme genres and anxiety-producing material. It's all free, easy to access, available within seconds, 24 hours a day, seven days a week.

This basic narrative, with its mixed techno/sex panic and vaguely scientific undertones, can be seen everywhere from New York magazine to consumer health sites, Esquire to The American Conservative to The Daily Mail, Christian websites to Thought Catalog. Many use a common tack: starting with a person or group of people who found porn to be problematic (a self-described porn or sex addict, members of the "No Fap" Reddit community), then extrapolating these experiences to make a more general warning about porn's detrimental effects. The genre subtly shames both women and men—the former for not being enough like porn stars to keep their men interested, the latter for letting their libido rule them—and often veers into discussions of whether more government intervention is warranted.

But the narrative at the core of this genre is a crock, according to a new study published in the journal Sexual Medicine. Researchers from UCLA and Montreal's Concordia University collected data from 280 (mostly young) men on the average number of hours per week they spent watching pornography (answers ranged from zero to 25); their sex drives more generally; whether they were in a monogamous relationship (123 were); and their erectile functioning. Participants also watched a very "vanilla" porn film in the lab and reported their arousal level.

The researchers found no relationship between pornography habits and experiencing erectile dysfunction among sexually active participants. "Many clinicians claim that watching erotica makes men unable to respond sexually to 'normal' sexual situations with a partner," said study co-author Nicole Prause, an associate research scientist at UCLA's Semel Institute for Neuroscience and Human Behavior. "That was not the case in our sample."

"These data suggest that inventing a new problem—porn causing erectile problems—for which there is no tested treatment, may be a disservice to patients," she continued.

Erection trouble in the study population was a product of issues such as "performance anxiety, poor cardiovascular health, or side-effects from substance abuse," said Jim Pfaus, a professor in Concordia's psychology and behavioral neurobiology department and the other study lead.

The researchers also found that men who watched more porn at home reported higher levels of arousal when they watched porn at the lab. "While one could object that this was expected since they like sex films," Prause said, "the result is important because clinicians often claim that men get desensitized by watching these films. Rather, "they are responding more strongly to very vanilla erotica than the guys for whom the films are more novel."

Participants who watched the most porn also reported feeling higher desire for sex with a partner.

"The positive relationships between [porn] viewing and many indices of sexual responsiveness suggest that [it] might even improve erectile functioning," the researchers concluded, noting that watching porn may prime men "to respond to different sexual stimuli types" in a way that "could facilitate their sexual responses to females who may vary tremendously in their sexual behavior preferences." Regardless, the "oft-repeated link between ED" and porn is mostly "perpetuated by data-poor literature."