Elf Sternberg

As regards the post title, actually the article says Mormons and evangelicals scored higher than atheists/agnostics when it came to questions on Christianity; the overall scoring difference was in breadth of understanding of other religions:

On questions about the Bible and Christianity, the groups that answered the most right were Mormons and white evangelical Protestants. On questions about world religions, like Islam, Buddhism, Hinduism and Judaism, the groups that did the best were atheists, agnostics and Jews.

I also note that "nothing in particular" was among the lowest scoring groups on the survey.