When you really care, say it with decent writing
And, to explain this chart, let's turn to the report itself:
Note that for each of the faith-based belief systems I've listed, the people who are the least serious about them write at the highest level. On the other hand, the people who are most serious about not having faith (i.e. the "very serious" agnostics and atheists) score higher than any religious groups.
So, in other words, if we look at religious groups overall without attending to religiosity, atheists appear to write essays with the highest reading level. However, if we break each group down into low, medium, and high levels of religiosity, we see a striking pattern. While atheists in general remain at the top (though they are surpassed by the least serious Buddhists), it's the most committed atheists who exhibit the highest reading levels. The same appears to be the case for agnostics- it is the most committed of the agnostics who write the best. In contrast, among the faith-based belief systems, the least committed appear to write the best. I am, as you might guess, reminded of the other recent finding that atheists know more about religion than most theists. In combination, these results seem to say some interesting things about the sort of people who become atheists or agnostics and the sort of people who don't.
Now, should we trust these results? Well, yes and no. On the down side, the OKCupid results are based on a very, very non-representative slice of the population- only those people who have accounts on OKCupid. On the upside, though, you can't fault their attempts to do as well with these data as possible:
We selected 526,000 OkCupid users at random and divided them into groups by their (self-stated) race. We then took all these people's profile essays (280 million words in total!) and isolated the words and phrases that made each racial group's essays statistically distinct from the others'.
So, at least it's a helluva lot of data drawn from a random sample of users. That's helpful, at least. More importantly, however, I think we should not take these findings to suggest that atheists and agnostics are better educated or smarter than theists. Certainly Satoshi Kanazawa would make this argument, and he might even be right, but the results from OKCupid don't say that. Likewise, previous research suggests that the mean education differences between various religious groups are pretty small. No, what I think OKCupid's results suggest is that when atheists want to appear attractive to others, they attempt to show off their intelligence and education, whereas when the very religious want to appear attractive, they do the opposite. What this means depends at least a little on your perspective- either that atheists arrogantly try to play up how smart they are, or that theists shamefully try to hide the same trait- but nevertheless the pattern of results is quite interesting.
I just wish we had data on scientologists.