I'm sure if this test were applied to all fundamentalist Abrahamics, there would be similar results (I read one further study cited that had similar results with Judaism, but I did not see one for Islam, though I only read two of the studies).

I encourage all atheists to either read their respective tomes (skeptic's annotated Tanakh/Bible/Koran is great for finding vaguely remembered verses) and especially to listen to what they say today. Hasidic Jews, Nation of Islam, or Assembly of God are good examples.

There are many recordings of their teachers (much in English) all over youtube, you can hear it directly from their mouths to your ears, nothing third hand.

Even a half an hour of the 700 club (like Fundie Light) can be very revealing, just pick a topic that you're curious about and see what they say.

It's horrifying. You won't believe it if you don't research it yourself, if I told you, you'd think I am making things up. It's crazy I still have to go back to it from time to time to remind myself that it's real, because you want to deny it, it's too awful.