The Federers, Epstein notes, did a lot of things that served their son well. For starters, once they learned that Roger loved playing sports, they encouraged him to try a variety of them—or to have a “sampling period,” as Epstein calls it in the book. Sampling periods are crucial, he argues, because they allow kids to discover organically what they love doing and most want to succeed in.

They’ve also grown less popular in recent years. In the first two decades of the 21st century, stories like those of Tiger Woods and the chess-playing Polgar sisters of Hungary*—whose parents homeschooled their three young daughters with the explicit intention of making them international chess celebrities (and succeeded)—seeped into the modern canon of parenting wisdom. Battle Hymn of the Tiger Mother, the 2011 book that encouraged parents to guide their children into rigorous training for specific activities as early as possible and not allow them to quit, became a best seller and helped contribute to the notion that kids need a “head start” if they are ever to achieve excellence. And outside of these famous examples, the increasing competitiveness and time demands of kids’ sports leagues and musical ensembles tend to necessitate that kids prioritize one activity over all others.

There’s a lot of concern among parents who follow these kinds of ideas, Epstein said, that without early specialization they’ll “miss” the next Tiger Woods, or the next Mozart. But that’s a somewhat misguided fear, “not only because of course that [kind of professional success is] very rare, but in both those cases a lot of the public consciousness is that they were created by their fathers, or manufactured,” Epstein said. “When in fact, in both cases the father started responding to the kid’s very unusual display of interest and prowess.” Indeed, in a study of 1,200 young musicians, overwhelmingly those who quit did so because they felt there was a mismatch between the instruments they wanted to learn to play and those they eventually took lessons in—and another study Epstein cites found that among musicians ages 8 to 18, the students who went on to become the most successful only started practicing more when they identified the instrument they themselves wanted to focus on. Tiger Mother author Amy Chua, Epstein notes in Range, begins to make sense of this herself at the end of her book, when her daughter Lulu, whom Chua has decided will be a violin prodigy, abruptly quits playing at age 13 despite showing extraordinary potential because, as Lulu puts it, her mother picked it, not her.

The other major principle that Epstein hopes parents will take away from Range is not just the acceptability but the importance of quitting. Quitting sports or music lessons or other activities, it should be noted, has also gotten controversial among parents. Some argue that, in line with the old adage “Quitters never win,” hanging in there when an activity becomes unfulfilling or hard builds character, or encourages the development of “grit.” But as Epstein points out, while the ability to persevere when something is difficult can certainly be a competitive advantage, in the long run so can knowing when to quit.