Britain, for example, has its Darwin skeptics, and its climate-change deniers, said the historian David N. Hempton, the dean of Harvard Divinity School, who is from Northern Ireland. “But the proportions are different,” he said, with British residents and evangelicals more likely to be comfortable with Darwin and climate science than their American counterparts.

He attributed the difference in part to Britain’s more unified national culture. “You can get school boards in the U.S. that will try to prevent the teaching of evolution in schools,” Professor Hempton said. “That’s almost impossible to do in Britain, because school curricula are set more nationally.”

American evangelicals and fundamentalists can secede into their own churches and Christian schools, and read magazines and watch television aimed at them, he said. But that is harder to do across the Atlantic, “where things like the BBC have a kind of generic influence over the whole culture.”