Horace Mann, often called “the Father of the Common School,” believed that universal public schooling was the best way to forge citizens for a democracy. He believed that uniform schools were key to making all people virtuous, which he envisioned as holding broadly Protestant religious beliefs and putting the common good, often through service to the state, ahead of self‐​interest.

Public schools are still thought to be crucial to forming good citizens, though the civic values they are expected to inculcate are secular. They should promote political knowledge and engagement, as well as cultivate inclusion and toleration of diversity. In 2016, U.S. Secretary of Education John King spoke about the importance of political engagement as part of a well‐​rounded public‐​school education. The public schools, because they are open to all, are thought to guarantee that all will obtain knowledge of how American government works, while simultaneously exposing students to diverse perspectives.

Private schools, on the other hand, are often assumed to be unreliable for promoting good citizenship. For one thing, they have the flexibility to promote the values of specific groups, which some fear will expose students to too narrow a set of perspectives. And there is no guarantee that they will provide civic knowledge, or promote values like tolerance, at all.

Ironically, studies show that private schools actually have a sizeable advantage over traditional public schools in promoting civic values and knowledge, perhaps precisely because they can embrace specific, concrete values.

A 2007 report examined the results of 21 quantitative studies tackling the effects of public and private school choice on 7 civic values: political tolerance, voluntarism, political knowledge, political participation, social capital, civic skills, and patriotism. Among the studies using more‐​rigorous controls for factors other than schools that could affect outcomes, the author reported, “12 findings indicate statistically significant positive effects of school choice or private schooling on civic values and 10 suggest neutral results. Only one finding…indicates that traditional public schooling arrangements enhance a civic value.” Of 36 total findings in the less‐​rigorous studies, 21 showed a choice advantage, 13 neutrality, and 2 an assigned public school advantage.

An analysis of 11 studies linking private school voucher programs to 3 civic values—tolerance, civic engagement, and social order—found large positive correlations between voucher use and civic values. The studies found that private school choice had a neutral to positive impact on tolerance, neutral to positive impact on civic engagement, and positive impact on social order.

In one of the studies, researchers asked students in the Washington, D.C. voucher program to identify groups such as the religious right and gay activists that they agreed with the least. The researchers then asked the students if they would allow members of the disliked groups to exercise free speech, run for president, and live in the same neighborhood as they did. Students that participated in the voucher programs were 50 percent more likely to answer “yes” to all three questions, associating the voucher program with increased tolerance.

One theory why students in private schools score higher on civic values is that in chosen schooling families and educators with shared moral, political, and social commitments can come together, enabling teachers to provide more concrete and rigorous content. In contrast, taking strong stands on questions such as whether the United States is a democracy or republic, or whether students have a moral obligation to volunteer in their communities, might be too controversial in public schools that bring in students based solely on their home address. Another possibility is that public schools that do not soft‐​pedal or ignore controversial material fuel conflict, leading to greater polarization among groups than existed before.

Consistent with what Neal McCluskey observed a couple of days ago in our School Choice Week series of posts, civic education reality may be very different from the promises of public schooling champions.