Nancy Jo Sales’s “American Girls” is the latest entrant in a genre of literature and non-fiction that might best be described as Girls In Crisis. The category includes everything from “Go Ask Alice,” Beatrice Sparks’s 1971 facsimile of the diary of a teenage girl descending into drug addiction; to the 1994 book “Reviving Ophelia,” which drew on author Dr. Mary Pipher’s therapy practice; to critiques of specific communities like “Little Girls In Pretty Boxes,” Joan Ryan’s 1995 investigation of abuses in figure skating and gymnastics.

It’s a genre that deserves careful scrutiny because it’s prone to hyperbole and panic-mongering. In “Go Ask Alice,” the subject of that anxiety was drug use. For Pipher in “Reviving Ophelia,” the concern was mass culture and the costs and benefits of a society that gave girls more freedom but granted them fewer protections. Ryan was concerned with what constituted excellence in hyper-competitive sports dominated by women. And in “American Girls,” Sales turns her attention to social media, and the supposedly catastrophic effect it’s having on teenage girls, mostly by interviewing many of them about how they live online.

“American Girls” might have been a more convincing — if less splashy — book had Sales made more modest claims about the influence of social media on American life and culture. And while a Girls In Crisis book requires the author to suggest that teenagers are on the brink of death or at least some very bad decisions, Sales doesn’t grapple with significant trends in the lives of American teenagers and with the testimony of her own subjects, who generally don’t seem terribly imperiled. But most of all, I couldn’t shake the feeling that Sales should have been writing a very different book, one about teenage boys who put pressure on their female friends and classmates, rather than the girls who work valiantly to make independent decisions.

In “American Girls,” Sales may hope for cultural change and suggest that tech companies like Apple ought to intervene somehow to protect girls from sexualization and harassment. But ultimately, the teenagers of “American Girls” have to stand alone against these forces, and Sales sometimes sounds rather irritated with them when they prove all too human.

One of the most significant tests of a book like “American Girls” is whether it actually proves Sales’s thesis, that “this seismic shift in how girls spend their time is having a profound effect on the way they think and act, as well as on how they make friends, the way they date, and their introduction to the world of sex.” This, I am afraid, is something “American Girls” fails to do.

When Sales tries to substantiate the idea that teenage culture is changing dramatically, she sometimes does so in ways that abuse statistics and obfuscate common sense.

“Studies have found that the number of middle-schoolers and high-schoolers who sext, with either word or pictures or both, is anywhere from just 4 percent to more than 50 percent,” Sales writes in one example. But which is it? And are the numbers the same at every age? The difference between 4 percent and 50 percent is the difference between a marginal behavior and a genuinely alarming phenomenon. In another example, just because a 2007 Pew Research Center study determined that lots of young people aspire to be rich or famous doesn’t mean they’re demonstrably more narcissistic than their predecessors, and even if they were, that the Internet is to blame.

This careless approach is a shame, because “American Girls” would be a more nuanced book if it grappled more deeply with the actual statistics about how American teenage girls live their lives. According to the Guttmacher Institute, which studies sexuality, contemporary teenagers are actually having sex for the first time later than their predecessors: between 2006 and 2008, just 11 percent of teenage girls between the ages of 15 and 19 had sex before they turned 15, down 8 percent from 1995. By 2010, teenage pregnancy was at its lowest rate in three decades, with significant decreases coming from 2008 to 2010 alone. Women’s enrollment in college has continued to climb even as men’s enrollment rates have stagnated.

None of these numbers mean that sexism has vanished, of course. Sales might have had a case if she argued more narrowly that social media broadcasts trying moments in teenagers’ lives more widely than would have been possible in an earlier era, which can mean that those moments can resurface again when a girl is applying to colleges or for jobs in a way that could have a long-lasting impact on her life. Alternatively, “American Girls” might be the sort of provocative intervention it aspires to be if Sales had reckoned with — or even acknowledged — figures like these and pondered whether a gap has opened up between teenage girls’ online and offline behavior, or how tech-enabled sexism seems designed to claw back the gains young women are making relative to their male peers in some areas.

Sales’s own reporting suggests the potential of digging into these contradictions. The girls she interviews are subject to invasive solicitations and significant peer pressure, but often seem resilient, intelligent and self-aware.

If I had a 13-year-old daughter who sent a picture of a naked mole rat to a boy who asked her for nude pictures, I’d be proud of her. Girls who declare that “Girls post pictures of their bodies and say they’re body positive and everyone’s like ‘You’re so beautiful’ … But they’re not body confident — they’re Photoshopping their bodies and editing their pictures” show an impressive level of self-possession. Girls who try to protect their drunk friends from being videotaped are doing the right thing. And girls who can choose their friends over boys who are behaving badly are building the sort of support networks that will serve them well in difficult times.

“American Girls” doesn’t build the case it ought to that teenage girls are materially in crisis. And when Sales turns her attention to the culture that surrounds her, she often chooses examples that are out of date or writes about culture in a way that suggests she’s less than familiar with the material.

Series like “Dance Moms,” “America’s Next Top Model,” “Jersey Shore” and “The Hills” may have “[depicted] women in conflict with one another, gossiping and backstabbing,” but only “Dance Moms” is still on the air. Sales talks about what it means to be a “cool girl,” without seeming to know that Gillian Flynn provided a handy guide to the trope in Flynn’s horror novel “Gone Girl.” And while it’s true that “Mad Men” main character Don Draper (Jon Hamm) may have been a chauvinist, he would never give the sort of pitch Sales imagines for him, where he castigates teenage girls by declaring that “They’re sentimental, they’re vain, they want to be popular, they want to show off their pretty clothes and who they’re friends with.”

As a critic of American culture, I’m fully aware that it’s a target-rich environment for anyone interested in rooting out sexist messages. But to make a powerful critique about the interaction between social media and pop culture, Sales might have been better off documenting how American culture has changed in recent years. It’s not terribly hard to do this: there are all sorts of efforts to track who appears on screen and how they behave. The rise of reality television along with the expansion of social media does mean that it’s both technologically possible to broadcast your life to a large number of people, and that there’s an available template for cultivating an audience.

Unfortunately, the accumulated result of Sales’s references, and the way they’re scattered throughout “American Girls” rather than concentrated in a few coherent argumentative sessions, is to make the book sound parental rather than analytical or authoritative. Sales may share your horror at the rise of the Kardashians, but doesn’t have enough critical distance to analyze the family’s appeal to young women. Among many other things, Kim Kardashian survived the kind of experience Sales worries might befall her subjects — a sex tape she made with an ex became highly, highly public — and refused to be destroyed by it.

If the technical weaknesses of “American Girls” are considerable, its attitude also feels curiously off-kilter. While Sales has spent an awful lot of time with teenage girls, “American Girls” often gives the impression she feels a certain amount of disdain for them.

Sales quotes Naomi Wolf’s “The Beauty Myth” to suggest that teenage girls have allowed themselves to be obsessed with their looks, despite the material gains young women have made in other areas. She paints an oddly rosy picture of a homeless teenage girl who carries a knife and travels with a man to try to avoid being raped, but has the great virtue of not being on social media anymore. Sales criticizes them for protesting dress codes, saying that these fledgling steps into feminist activism seem “strange at a time when there are so many other issues facing them.” Sales ignores the idea that school-level policies are the rare area where girls might be able to make their voices heard and suggests instead that this is an area of feminism that “doesn’t criticize boys.”

Sales, of course, has chosen to write a book about teenage girls, rather than the teenage boys who ask her sources for nude pictures, pressure them for sex and shoot video of them when they’re drunk to the point of incapacitation.

And towards the end of the book, Sales puzzles over teenage girls’ sexual behavior, demanding to know “Why aren’t teenage girls and women insisting that boys and men wear condoms? Why are women acquiescing to the preferences of their male sex partners, gambling with their own health and well-being?… So why are women leaving the question of condoms up to men? Why, again, are they being passive?”

What Sales doesn’t seem to realize, though, is that she’s treating young women exactly the way boys and men do. The males of the species will run wild, ask for naked pictures of very young girls, resist condoms and fail to ask for consent. The culture girls live in will go on poisoning them. It’s girls who are supposed to struggle to set limits, to say no, to expel those toxins and to live up to vastly higher moral standards. And if they don’t, or if they fail to resolve the contradictions that are built into the expectations girls face everyday, Sales and teenage boys alike will judge them for it. “American Girls” is the sort of book that poses as a solution to the challenge teenage girls face, but actually profits from being part of the problem.