Sometime between when we were children and when we had children of our own, parenthood became a religion in America. As with many religions, complete unthinking devotion is required from its practitioners. Nothing in life is allowed to be more important than our children, and we must never speak a disloyal word about our relationships with our offspring. Children always come first. We accept this premise so reflexively today that we forget that it was not always so.

In our recently published book, Sacred Cows, we took on our society’s nonsensical but deeply ingrained beliefs surrounding marriage and divorce. We often get asked whether we will next address the sacred cows of modern parenting, at which point we ask the speaker to please lower his voice, and we look nervously over our shoulders to make sure that nobody has overheard the question.

To understand the frightening power of the parenthood religion, one need look no further than the 2005 essay in The New York Times by Ayelet Waldman, where the author explained that she loved her husband more than her four children. On “Oprah Where Are They Now,” the author recently reaffirmed the sentiments reflected in her New York Times article, and she added that her outlook has had a positive impact on her children by giving them a sense of security in their parents’ relationship. Following the publication of her essay, Waldman was not only shouted down by America for being a bad mother; strangers threatened her physically and told her that they would report her to child protective services. This is not how a civil society conducts open-minded discourse. This is how a religion persecutes a heretic.

The origins of the parenthood religion are obscure, but one of its first manifestations may have been the “baby on board” placards that became popular in the mid-1980s. Nobody would have placed such a sign on a car if it were not already understood by society that the life of a human achieves its peak value at birth and declines thereafter. A toddler is almost as precious as a baby, but a teenager less so, and by the time that baby turns fifty, it seems that nobody cares much anymore if someone crashes into her car. You don’t see a lot of vehicles with placards that read, “Middle-aged accountant on board.”

Another sign of the parenthood religion is that it has become totally unacceptable in our culture to say anything bad about our children, let alone admit that we don’t like them all of the time. We are allowed to say bad things about our spouses, our parents, our aunts and uncles, but try saying, “My kid doesn’t have a lot of friends because she’s not a super likable person,” and see how fast you get dropped from the PTA.

When people choose to have children, they play a lottery. Children have the same range of positive and negative characteristics as adults, and the personalities of some children are poorly matched with those of their parents. Nature has protected children against such a circumstance by endowing them with irresistible cuteness early on, and by ensuring that parents bond with children sufficiently strongly that our cave-dwelling ancestors didn’t push their offspring out in a snowbank when they misbehaved. Much as parents love their children and have their best interests at heart, however, they don’t always like them. That guy at the office who everyone thinks is a jerk was a kid once upon a time, and there’s a pretty good chance that his parents also noticed that he could be a jerk. They just weren’t allowed to say so.

Of course, Ayelet Waldman’s blasphemy was not admitting that her kids were less than completely wonderful, only that she loved her husband more than them. This falls into the category of thou-shalt-have-no-other-gods-before-me. As with many religious crimes, judgment is not applied evenly across the sexes. Mothers must devote themselves to their children above anyone or anything else, but many wives would be offended if their husbands said, “You’re pretty great, but my love for you will never hold a candle to the love I have for John Junior.”

Mothers are also holy in a way that fathers are not expected to be. Mothers live in a clean, cheerful world filled with primary colors and children’s songs, and they don’t think about sex. A father could admit to desiring his wife without seeming like a distracted parent, but society is not as willing to cut Ms. Waldman that same slack. It is unseemly for a mother to enjoy pleasures that don’t involve her children.

There are doubtless benefits that come from elevating parenthood to the status of a religion, but there are obvious pitfalls as well. Parents who do not feel free to express their feelings honestly are less likely to resolve problems at home. Children who are raised to believe that they are the center of the universe have a tough time when their special status erodes as they approach adulthood. Most troubling of all, couples who live entirely child-centric lives can lose touch with one another to the point where they have nothing left to say to one another when the kids leave home.

In the 21st century, most Americans marry for love. We choose partners who we hope will be our soulmates for life. When children come along, we believe that we can press pause on the soulmate narrative, because parenthood has become our new priority and religion. We raise our children as best we can, and we know that we have succeeded if they leave us, going out into the world to find partners and have children of their own. Once our gods have left us, we try to pick up the pieces of our long neglected marriages and find new purpose. Is it surprising that divorce rates are rising fastest for new empty nesters? Perhaps it is time that we gave the parenthood religion a second thought.