Remarkably, less than half of the interfaith couples in my survey said they’d discussed, before marrying, what faith they planned to raise their kids in. Almost four in five respondents (in both same-faith and interfaith marriages) thought having “the same values” was more important than having the same religion in making a marriage work.

The sentiment is understandable, even admirable, but often unrealistic. I found that interfaith couples were less satisfied than same-faith couples by a statistically significant margin — and that the more religiously active spouse (as measured by attendance at religious services) tended to be the unhappier one.

Certain faith pairings seem more likely to result in divorce. While roughly a third of all evangelicals’ marriages end in divorce, that figure climbs to nearly half for marriages between evangelicals and non-evangelicals. It is especially high (61 percent) for evangelicals married to someone with no religion. (My definition of interfaith marriage did not include couples from different evangelical, or different mainline, denominations.)

Evangelicals and black Protestants in interfaith marriages reported the least satisfaction. Mormons, remarkably, reported high levels of satisfaction — in interviews, some expressed confidence that their spouses would eventually convert. Catholics in interfaith marriages were no more likely to divorce than those married to other Catholics.