According to their critics, private Christian schools foster an attitude of isolation and withdrawal from society. And according to their boosters, public schools provide a unique and essential preparation for citizenship in a diverse nation. For the past five years, my colleagues and I at Cardus have been studying these claims, and last week, we released a new study that shows just how little data exists to support them.

Do private schools (whether religious or not) foster social isolation? Do public schools uniquely help to create the “social capital” that comes from diverse friendships and working relationships? Based on the data we released last week, the answer seems to be no on both counts. Adult graduates of Evangelical Protestant, Catholic, non-religious private, and public schools were all as likely to have a close friend who was an atheist or of a different race. The only statistically significant difference we found was that Evangelical Protestants were marginally less likely to have a close gay or lesbian friend—about 57 percent of evangelical Protestant graduates, compared to 69 percent of public school graduates, report a friend or relative who is gay or lesbian.

The Cardus survey, collected in March 2014 and analyzed by the team at the Cardus Religious Schools Initiative at the University of Notre Dame, was designed to give a comprehensive account of how different kinds of high schools contribute to the academic achievement, cultural engagement, and spiritual formation of their graduates.

The results of this survey were mostly consistent with a similar survey we conducted in 2011. While it’s inevitably most interesting to look at the differences among graduates of these different kinds of schools—more about those in a moment—one of the most striking results is the similarities. On more than half of the over 500 slides of results (available for free download along with the report at, there are no statistically significant differences between the various schooling types.

Some will find these similarities comforting, while others will find them disconcerting. Within the educational establishment policy and research community, they are at the very least surprising, not least because of the implications for public funding of private alternatives to government-run schools. In a panel discussion at Roosevelt House in New York City on September 10th after the results were released, former New York State Commissioner of Education David Steiner asked: “If the results are the same, is there any justification for not publicly funding private schools?”

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There are differences between the graduates of different kinds of schools, to be sure. Evangelical Protestant graduates marry younger, have more children, divorce less, and are more active in their church communities than other graduates—although, confounding rumors of evangelical isolation, they are more active in their broader communities as well. Academically, Evangelical Protestant school graduates look quite similar to public school graduates. Evangelical Protestant male graduates are more likely than others not to go beyond high school, representing a greater occupational involvement in the trades, but (confounding still more rumors, this time of evangelical sexism) Evangelical Protestant female graduates are as equally likely as those from other sectors to pursue tertiary education.

Another significant difference between Evangelical Protestant graduates and others is that they are less likely than others to pursue majors and careers in STEM (science, technology, engineering and math)–related occupations. They are more likely to be employed in education, health, and other social science-related occupations (the “caring professions”). When it comes to choosing a career, financial reward seems to have a lower priority in their decision-making process. They are much more likely to pursue a career based on a sense of “calling from God” or vocation than their counterparts from other school types.

Catholic school graduates, on the other hand, tend to look more like graduates of non-religious private schools—for these graduates, the various measures of academic attainment are consistently higher than other sectors. Catholic graduates tend to be employed in STEM occupations as well as disproportionately in managerial and professional occupations, especially in fields related to finance. At the same time, our study confirmed the 2011 finding that Catholic schools do not seem to be producing the spiritual formation results that most Catholic parents would presumably aspire to when choosing Catholic education for their children.

There was one other intriguing result among the graduates of private schools that are not religious (neither Evangelical nor Catholic)—they gave relatively positive evaluations of the contribution of their schools to their religious and spiritual formation. (As with all these findings, the sample here was controlled for socioeconomic and religious backgrounds in order to enable “apples to apples” comparisons.) Although non-religious schools are by definition officially secular just like public schools, it would seem that non-religious private schools are much more open and supportive of the religious expression of their students. Perhaps this is because many non-religious schools originated as religious schools; perhaps it reflects the public schools’ hypersensitivity to any religious expression. Whatever the cause, the results are striking.

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One final finding should not be overlooked: the “satisfaction” results in which respondents were asked to evaluate how well their high school prepared them for various dimensions of adult life. Every one of the private school types have significantly more positive evaluations in this domain, in almost every measure, than public schools. One might argue this is to be expected, given that tuition was paid for the private school experience, but that alone can hardly explain the dramatic gap.

Our project isn’t intended to be the last word. Rather, we seek to bring reliable data into the discussion, so that those interested in the pros and cons of the various school sectors can make more informed choices. And we hope those involved in education will take an opportunity to look in the mirror this survey provides. Ultimately these results matter for all of us—most of all because they debunk the myth that religious schools are somehow deficient in creating the social capital necessary for a vibrant democratic society. As it turns out, that couldn’t be further from the truth.

Ray Pennings is a co-founder and Executive Vice-President of Cardus. He chaired the research team that oversaw, evaluated, and reported on this research.