There is another popular theory for parents’ worry, advanced by evolutionary psychologists. Parents across the ages have certainly experienced the savage loss of a child — from a farm accident, a streetcar, the flu. But today, as birthrates have plummeted, perhaps we somehow see our children as even more precious than we once did.

“No mother of ten children will tell you ‘It’s OK I lost one child,’ ” says David Anderegg. “But if you have ten kids, let’s face it, you cannot be as invested in every child. One strategy, from an evolutionary standpoint, is to have as many children as possible and hope some will survive; the other is have very few and invest heavily in their care.”

With more first-time parents than ever older than 35, there is also the challenge of having children as fertility wanes. One mother I spoke to, whose second child is one of the estimated 5 million worldwide born to date using fertility treatments, wonders if this highly intentional (and expensive) form of conception creates on some level a fiercer biologic impulse to protect those hard-won offspring.

This culture of not trusting anyone, of never outsourcing child care, has a significant unintended consequence, especially for women: It inhibits our ability to turn to other pursuits, like, say, full-time work. “It has become almost superstitious,” says Skenazy. “A ‘good parent’ always has their eyes on their child. Any time you take your eyes off your child — poof! — they’re in danger. Omniscience used to be God’s job. We have outsourced God’s job to us.”