That is, a black person who is otherwise educated might use a phrase that makes perfect sense to other black people (e.g. "where dey do dat at?"; often used to express confusion at someone's ridiculous behavior) but that isn't clear to the mainstream. Latinos may pepper their profiles with Spanish words.
Asians might do this too if there wasn't so much ethnic/linguistic diversity among the Asian American population. As such, they likely use "safe" mainstream wording.
All this is to say that there are reasons that have nothing to do with intelligence that could have caused this sort of result.
* Unlikely, but hey, I might as well bring it up, since we're talking about flaws in the analysis.
Actually they're using the Coleman-Liau Index, a computer readability formula going back to 1975.
So what does this chart predict? That certain self-selected religious categories in their dataset correlate with word length in the essays. Is that good statistics, or a confirmation of prejudices, ie, religious people are less intelligent?
With all of those charts they passed over with "no comment", they saw fit to make a joke about a "Comic Sans Bible".
It bothers me because it statistically shaky and baldly prejudiced. I would love to have a conversation about that, and I wish people would engage instead of downvote.
I especially "enjoyed" the break down by race. They admit that the site is primarily American in demographic, but there is no accounting for language proficiency being a barrier to entry to the site for users from non-English speaking cultures. If you care enough to learn English as a second language to the point where you can use OkCupid, then I expect you will learn to to a greater degree than a minimally literate, native English speaker.
http://en.wikipedia.org/wiki/Religiosity_and_intelligence#St....
Are you then prepared to defend the same conclusion about the race vs word length chart? Or will you start looking for confounding factors, eg, Latinos trend Catholic? If so, think about why you accepted the religion claim on its face, but examined the race claim more carefully.
So, there is at least an apparent correlation between word length and intelligence for whatever that's worth.
If you're trying to draw me into a race/intelligence discussion based on possible implications of the correlation... no thanks.
At the end of the day, of course, correlation does not imply causation. If either religious people get their panties in a bunch and overly-defensive or irreligious people start gloating, both are simply demonstrating that their dogma is overriding their intelligence.