It’s back-to-school season and many parents may be wondering what’s the best choice for their toddlers: to pre-school, or not to pre-school? That is the question—but wife and mother of four Kerry McDonald offers some lessons from an unlikely source that should help some parents feel better:

On the best-seller wall of my local bookstore is Mo Willems’s new picture book, ‘The Pigeon HAS to Go to School! My children adore Mr. Willems’s books, but he’s got one thing wrong: The pigeon doesn’t have to go to school.

McDonald is the author of Unschooled: Raising Curious, Well-Educated Children Outside the Conventional Classroom and Senior Education Fellow at the Foundation for Economic Education (FEE). In her latest Wall Street Journal op-ed, McDonald explains that parents feel a lot of pressure these days to enroll their children in school at younger and younger ages.

The intensified push among Democratic presidential candidates for universal, subsidized preschool doesn’t help. But it’s worth remembering that while such concepts “reading by kindergarten” are taken as gospel now, twenty years ago more than two-thirds of kindergarten teachers disagreed.

When it comes to early education, McDonald explains that parents should weigh the trade-offs. Proponents claim preschool puts children on a stronger academic trajectory, but McDonald notes that’s not always the case.

Research has long shown that many students from disadvantaged backgrounds show short-term academic gains from preschool, but those gains quickly fade out. She cites other research showing that children who were enrolled in kindergarten one year before their peers born after many states’ September 1st cutoff dates were 30 percent more likely to be diagnosed with attention-deficit/hyperactivity disorder—especially boys.

What’s more, McDonald explains, standardized curricula that pushes little ones to achieve academically before they’re developmentally ready can put children who don’t meet such benchmarks at higher risk of being labeled or even medicated.

In her work with families McDonald finds a common theme among parents who delay of even forgo formal schooling altogether is that:

They are disillusioned with a model of mass schooling that rewards conformity over creativity…They want to nurture their children’s curiosity and originality, not watch these qualities eroded by one-size-fits-all schooling. These families seek alternatives to formal schooling.

McDonald concludes that Willems’s pigeon was afraid to go to school, and fear shouldn’t drive parents’ decisions about their children’s education, including whether to enroll them in formal school at all:

So, no, the pigeon doesn’t have to go to school. He can stay in the nest and soar when he’s ready.