When I was deciding whether to have children, in the early 2000s, most of what I read about the prospect was negative. Articles detailed the sleep deprivation, the physical challenges of pregnancy, the sheer overwhelmingness of motherhood. If you want to be happy, these writers warned, don’t have children. You might not want to get married, either—after all, marriage, research suggested, mostly benefits men.

Friends and family had few positive things to say, especially about parenting. When I asked parents I knew about the disadvantages of having children, I got an earful about tantrums, child-care difficulties, and the lack of time to yourself. “You don’t sleep for 18 years,” one cousin confided. When I would ask about advantages, there was usually a long, awkward pause. “It makes you less selfish,” one aunt offered—not a convincing argument for a fiercely independent, career-minded woman such as myself …

But are married mothers actually less happy than single women without children?