Si -- they should have corrected for second languages and proficiency, if they were serious. My big beef is the implication that word length obviously correlates with intelligence instead of, say, pretention.
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.