What Americans Know About Religion.

Pew's interesting new survey of public knowledge about religion.

For now, a few comments:

1. Overall, knowledge was relatively low (an average of 14 questions correct out of 32 mostly fairly simple ones). People did do better on questions about Christianity, though still got a lot wrong. It's worth noting that the data overstates the true level of knowledge because these are all multiple choice questions, and people can score "points" by guessing. If you guessed randomly on all 32 questions, you would get 8 right, on average.

2. As in the 2010 version of this survey (which asked different questions), Jews, atheists, and agnostics score better than other groups. In the earlier survey, Mormons also scored well, whereas on this one they are right at the national average. Evangelicals, by contrast, did better this time around. I suspect this is more a matter of the selection of questions than actual increases or decreases in knowledge levels of Mormons and Evangelicals. Worth noting that Jews, atheists, and agnostics score higher even if you control for education, income, and other demographic factors correlated with knowledge.

3. Most people greatly overestimate the percentage of both Muslims and Jews in the population. This is not inherently bad, but other studies suggest that overestimation of a group's numbers tends to be correlated with various forms of bias against it.

4. Public ignorance about religion strikes me as less rational, on average, than ignorance about politics.