JUST one extra year of schooling makes someone 10% less likely to attend a church, mosque or temple, pray alone or describe himself as religious, concludes a paper* published on October 6th that looks at the relationship between religiosity and the length of time spent in school. It uses changes in the compulsory school-leaving age in 11 European countries between 1960 and 1985 to tease out the impact of time spent in school on belief and practice among respondents to the European Social Survey, a long-running research project.

By comparing people of similar backgrounds who were among the first to stay on longer, the authors could be reasonably certain that the extra schooling actually caused religiosity to fall, rather than merely being correlated with the decline. During those extra years mathematics and science classes typically become more rigorous, points out Naci Mocan, one of the authors—and increased exposure to analytical thinking may weaken the tendency to believe.

Another paper, published earlier this year, showed that after Turkey increased compulsory schooling from five years to eight in 1997, women’s propensity to identify themselves as religious, cover their heads or vote for an Islamic party fell by 30-50%. (No effect was found, however, among Turkish men.) And a study published in 2011 that looked at the rise in the school-leaving age in Canadian provinces in the 1950s and 1960s found that each extra year of schooling led to a decline of four percentage points in the likelihood of identifying with a religious tradition. Longer schooling, it reckoned, explains most of the increase in non-affiliation to any religion in Canada between 1971 and 2001, from 4% of the population to 16%.

The most recent paper also showed that each extra year in the classroom led to a drop of 11 percentage points in superstitious practices, though these remain common. Two-fifths of respondents said they consulted horoscopes, and a quarter thought that lucky charms could protect them. Other research has shown that religious beliefs and practices seem to make people happier, and in some circumstances healthier and wealthier, too. But to argue that such benefits more than offset the gains from extra education would require a leap of faith.

* “Compulsory schooling laws and formation of beliefs: education, religion and superstition”, by Naci Mocan and Luiza Pogorelova. National Bureau of Economic Research, October 2014