In Girl Land (Reagan Arthur),a collection of boldly prescriptive, occasionally autobiographical essays, provocateur Caitlin Flanagan paints a picture of teen girlhood in which men and boys can be dangerous, the prom—that last bastion of romance—is “some kind of bacchanalia,” and girls are more insecure than ever. “The sexually explicit music . . . the crudeness of the common conversation, the ways that technology has made it so that there is almost no such thing as a private experience anymore—all of this is hard on everyone, but I would contend that it is most punishing to girls,” she writes. And while Flanagan doesn’t have a daughter herself, she’s not shy about telling parents to keep the Internet out of girls’ rooms and to make sure fathers supervise their daughters’ dating lives. Whether or not you agree, you’ll be absorbed by her commentary on the glamorous marketing of sanitary products and the now-slippery definition of virginity. To Flanagan, leaving the psychic space she calls Girl Land is a loss, but if parents protect their daughters, they “will be stronger and more confident” when they arrive on the other side.