If you had any doubt that man is an imitative creature, look up “TikTok and Tourette Syndrome.” Apparently, teen girls are developing symptoms of the nervous system disorder through watching TikTok. Following the rise of several Tourette influencers and Tourette accounts, doctors report that teen girls are developing the same tics as their favorite account holders.

Interestingly, the majority of these tics—and the majority of the account holders’ behaviors—“don’t look like Tourette syndrome” to the doctors who are seeing them, and who saw double or more the number of Tourette patients in 2020 than in previous years. But all of the patients spent time on social media prior to showing symptoms. The majority of those affected are adolescent girls.

It’s not just TikTok; Instagram has also launched Reels, meaning even if you never downloaded the Chinese-owned app onto your phone, you still have access to an addictive, permanent scroll of algorithm-generated video clips, and all of its delightful side effects, now including Tourettes.

Most of us already had a gut feeling about these new trends—like the transgender craze that has record numbers of young girls coming out as “trans men,” despite no previous evidence of gender dysphoria—without having to be told. We know social media is bad for our health, and we know girls around the ages of 11-18 years are especially susceptible to the social contagions spread online. But even if we didn’t have that gut instinct, even if we are inherently trusting of technology and friendly to social media, the results are impossible to miss. Social media is making young women seriously sick—in some cases, with permanent damage.

Facebook has been under fire recently for its knowing abuse of teenage anxiety to propel the success of its addictive platforms. “Facebook Knows Instagram is Toxic for Teen Girls,” the Wall Street Journal reported. For its own part, Facebook claims it didn’t know a commoditized social life with follower counts and like tallies would have a negative effect on the demographic most sensitive to social pressure; moreover, the company claims, its platforms still have a net positive effect.

It’s hard to imagine even the most eager employees at the company are actually that divorced from reality. Turns out, they aren’t. But those trends that make social media so toxic for young girls are the same ones that make these girls the ideal users and therefore the target audience for apps that flourish on high screen time. Teen girls fall into the addictive algorithms willingly, obsess over follower count, quickly adapt their behaviors to their peers, and spend more time on the platform than anyone else. Of course Facebook is not going to stop that.

Man is mimetic. Plato and Aristotle knew this; it’s why the music of the best regime had to be so meticulously guarded, and why the philosopher wrote at length in the Poetics of the importance and the shape of good art. Our habits are shaped by the media we consume, as well as the people we are surrounded with. The same goes for social media, which fuses these two realms of influence and takes the filter off.

Online platforms have replaced real life for most girls today, as Abigail Shrier describes in Irreversible Damage, her 2020 book on the transgender contagion among teen girls, which she argues is spread almost single-handedly through social media. The average Gen Z teen spends less time interacting with her friends in person than previous generations—at least an hour less every day—and hours more interacting with strangers online, who edit their images to perfection. This is a major reason why social media causes such extreme anxiety in puberty-age girls: Already insecure, they also spend the majority of their time with people who appear to be without flaw. With fewer opportunities than ever to grow a thick skin through human interaction, and fewer occasions to observe others do the same (importantly, to see others fail), these girls are terrified of—and terrible at—human interaction. The problem becomes the cure, as internet offers an escape.

The result, for these young women, of exchanging real, healthy life for the abysses of the internet, is life changing. Literally. It’s not just that girlish fads are growing increasingly disturbing, it’s that social media has succeeded by elevating niche and dangerous behaviors in a way real life never could have. As always, the internet does its best work in the dark—the realms of the repugnant and the weird. Once, a 15-year-old girl would have been convinced that a digital pet on a keychain was the hottest new accessory (remember Tamagotchis?). Now, she’s developed a nervous system disorder, an eating disorder, started cutting or contemplating suicide, or come out as “trans,” ready to get a double mastectomy and inject male hormones that will permanently prevent her from having children. Because having tics is quirky and cool.

The pandemic escalated the problem, as the Tourette doctors point out. The average teen girl went from seeing friends less often than previous generations to seeing them never. The only place she could continue to prove her social clout and gain approval was online. Perhaps the only industry other than Amazon to profit immensely off communal lockdowns, social media companies saw record breaking hours of screen time during the pandemic.

What happens to these girls when they grow up? Even if they recover from the serious side effects of a life lived wholly online, old habits die hard. The Wall Street Journal interviewed several young women in its story on Instagram toxicity, and many said the same thing: They know Instagram is bad for them, but they fear missing out or can’t kick the addiction. Most said they didn’t want the app to disappear, despite its harmful effects. Addiction to the machine is real.

The apps that caused these teenaged epidemics are intangible, but their effects are real. It should not be a dramatic proposal, in light of these illnesses, to suggest parents restrict or even eliminate social media use for their children, especially where their children do not yet have the self-control to free themselves. Other proposals are more extreme. And yet, this addictive substance has, in thousands of cases, played on young girls’ weaknesses to the detriment of their very lives. It’s worth asking what benefits, if any, are worth that cost.