A major shift in the 20th century was that parents came to rely heavily on expert guidance, but they were primarily interested in what other Americans recommended. "They didn’t look positively toward Europe or elsewhere, because they thought of American culture as superior and exceptional,” Fass said.

Read: There used to be a consensus on how to raise kids

More recently, though, in the past few decades, the comparisons Americans make between the U.S.—where the ideal of hands-on, “intensive” parenting is the new normal—and other parts of the world come with more humility. Fass attributes this to a set of three interconnected developments. First, “the United States doesn’t see itself as any longer in the same economically privileged situation that it was in in the past,” she said. America’s economic primacy has been contested by the dynamism of several countries, particularly European and Asian ones, which leaves American parents concerned that their kids won’t succeed in a hypercompetitive, globalized economy.

Second, and relatedly, international standardized testing that compares various countries’ educational systems has given Americans a sense of how unremarkable theirs is. For instance, in the first Program for International Student Assessment, or PISA, in 2000, students in the U.S. were shown to have middling math and reading skills, giving American parents a sense that their children had fallen behind those in other wealthy countries. A decade later, after Chinese students first participated in PISA and performed best in every category, the secretary of education at the time, Arne Duncan, said, “We can quibble [with the results], or we can face the brutal truth that we’re being out-educated.”

The third factor Fass cited was the entry of large numbers of women into the workforce, which—because men rarely take on an equal share of child-care duties—made motherhood “a much more fraught experience than it used to be,” Fass said. For all the opportunities that working opened up to women, being an attentive parent was easier when it wasn’t being balanced with professional duties. These three trends established a sense of insecurity and, therefore, a market for international parenting books. (Perhaps more Americans would be interested in parenting books focused on the global South if children there were outperforming American kids on standardized tests.)

Druckerman was working on Bringing Up Bébé as these trends were about to crest, even if she says she wasn’t looking to capitalize on them. At the time Bringing Up Bébé was published, Americans (particularly affluent ones) were already a decade or two into practicing helicopter parenting; a dispatch from a land where child-rearing was relatively more laissez-faire naturally held appeal.

“More than anything,” Druckerman told me, echoing Fass, “there was an ambient feeling of insecurity and a realization that we may not have the best recipe for everything, and that people in other countries have things to teach us." She sees this playing out in other realms too, as journalists and policy experts have looked abroad to see, for instance, how other countries legislate gun safety and health care.