Studies have repeatedly found that private schools produce more knowledgeable and tolerant citizens than public schools

See The Core Content Paradox by Neal McCluskey of Cato.

"Last week, Heterodox Academy hosted an engaging web discussion between Greg Forster of EdChoice and Robert Pondiscio of the American Enterprise Institute. The topic was “School Choice and Viewpoint Diversity,” with Forster arguing that choice is likely to yield greater diversity of ideas in classrooms, and Pondiscio averring that choice will reduce diverse discussion by enabling families to select schools in which all agree.

This is a bedrock education topic—what is the best way to deliver education in a diverse society?—and both debaters took reasonable positions. Pondiscio’s was the more intuitive: With unbounded choice, people will split into isolated camps. But the evidence on choice and cohesion suggests a paradox: More freedom appears to foster greater unity.

Forster discussed some of this evidence, having done a lot of work over the years compiling and analyzing research on private school choice and formation of knowledgeable, tolerant citizens. Patrick Wolf of the University of Arkansas updated the state of that research in our 2020 book School Choice Myths. Including after controlling for such confounding student characteristics as family income, studies have repeatedly found that private schools produce more knowledgeable and tolerant citizens than public schools. Similar results have been found for charter schools.

Why?

There are likely many reasons, but as Forster argues, families are more likely to trust schools they have chosen than those they have not to have honest, open discussions about contentious issues. This is consistent with well‐​known work by sociologist James Coleman, who found that Roman Catholic schools are more effective, at least at graduating students, than public schools, because they are rich in social capital: trust among students, school employees, and parents. Such trust likely translates into private school parents being more likely than those in public schools to feel confident that a teacher who opens a discussion on a controversial issue will not try to impose an objectionable viewpoint on their children. Of course, private school parents can also take their kids and money out of schools they are unhappy with, lowering the stakes of what a school does and decreasing the indoctrination threat.

On the flip side, research on public high school biology teachers, and examinations of how content for diverse students is created, indicates that when a subject is controversial, public schools tend toward lowest‐​common‐​denominator stuff the minimizes the risk of giving offense. Instead of rigor, kids get pablum.

Pondiscio faults some school choice supporters, especially those of a more libertarian bent, for disregarding the need for unifying content. He may be on to something, at least in terms of messaging: Talking about freedom and market competition too much gives the appearance of ignoring what actually goes on in schools. That includes whether deep, time‐​honored content is taught, the kind that professor E.D. Hirsch has argued for decades is necessary not just to build national bonds, but enable children to understand allusion‐​filled things they read. Pondiscio suggests that we look in a more “pluralist” direction than unfettered choice in order to expand the reach of unifying, rigorous content. So choice of schools, but with at least some common content required by government.

The key problem with this approach is that a central authority will have to choose what to require.

That immediately endangers social and political minorities, as Forster rightly emphasizes in the discussion. If you think liberty and equality under the law are more important than government‐​coerced unity, such bounding of choice is untenable. That said, a pluralist system would be better than the current default: assignment to a public school based on one’s home address.

But here we see the paradox again: Letting diverse people decide for themselves what is important to learn appears to make it easier to get the sort of rigorous, time‐​honored content Pondiscio, Hirsch, and others think is essential.

If you are old enough to remember when Hirsch’s Cultural Literacy was published in 1987, with its huge appendix of names, ideas, and concepts Hirsch thought all kids needed to know to thrive in American society, you will recall how controversial it was. Some thought it terrific, others too focused on dead white men. Eventually, Hirsch lamented the “thoughtworld” dominating colleges of education, where teachers were formed, that would not let Hirsch’s ideas in.

So where is the Core Knowledge curriculum, born of Cultural Literacy, most likely to be found? Schools of choice.

According to the most recent data from the Core Knowledge Foundation – alas, 2008 – Core Knowledge schools were 44 percent traditional public, 35 percent charter, and 21 percent private. Using the closest, readily available federal data, in the 2010-11 school year, about 5 percent of public schools were charters, and in the 2009-10 school year 22 percent of all K-12 schools that were not primarily preschools were private. A quick sampling of the Core Knowledge Schools map suggests that roughly the same proportions exist today.

Clearly, Core Knowledge schools are disproportionately chosen, especially charters. And many private schools, which are often religious, likely have their own curricula similar to Core Knowledge. Why the disproportion? Probably because educators and families need to be able to agree on a content‐​rich, rigorous curriculum for it to be accepted and sustainable, and that is easier achieved when like‐​minded people can come together.

Intuitively, you would think to get rigorous, core content in schools, it would have to be imposed from above. But the evidence suggests a paradox: If you want unity and rigor, you have to set people free."