72.8% of the 3226 philosophers who took the PhilPapers survey in 2009 said that they accept or lean towards atheism. Among philosophers of religion, though, 72.3% accept or lean towards theism. Adriano Mannino considers the question in a post at the group blog Crucial Considerations. Of these figures, he writes:



On the face of it, there are two hypotheses which could explain the data, one of them worrying for atheists, the other less so:



Expert Knowledge: Philosophers of religion possess expert knowledge on the arguments for and against God’s existence. The arguments for God’s existence are just overall more convincing and render God’s existence more probable than not.



Selection Bias: People often become philosophers of religion because they are religious, or at least have a high credence in God’s existence. Theist often become philosophers of religion, not the other way around.



He then makes use of the results of the data from the study by Helen De Cruz (VU University Amsterdam) of why philosophers of religion went into that field and how their beliefs concerning theism and atheism changed over time. He ends up concluding that the evidence is best explained by the “selection bias” hypothesis. He says: The theists to atheists/agnostics ratio is even higher before exposure to PoR. This confirms the impression we got from considering philosophers’ motivations for doing philosophy of religion: most philosophers of religion were already theists when they started, so there is a strong selection bias at work. Moreover, there are more philosophers of religion updating their beliefs toward atheism and agnosticism than toward theism, ....The numbers show that the ratio of theists to atheists/agnostics declines with exposure to philosophy of religion. LINK.

Why? I'll tell you why. Because theists gravitate to that field, that's why. In fact, given that they do gravitate to that field, the fact that there aren't MORE theists working in it tells us something interesting about the philosophy of religion (PoR) itself. I've been arguing that the PoR should end in the secular universities. A new study confirms what I'm saying since the discipline isn't even able to keep those believers who enter it! That's the take away from a recent study of the figures. You will see a link to my post calling for an end to the PoR embedded there.To read my series of posts calling for the end of the PoR thery're right here in reverse chronological order.