A bit of social science out of Belgium:
http://www.theblaze.com/news/2017/07/03/religious-people-are-more-tolerant-open-minded-than-atheists-new-study-reveals/
If you’re interested in pursuing this topic further (as I am), the original study is available online here:
“Are atheists undogmatic?”
Fortunately for me, I have access to a university library and its resources.