I was reading this article earlier as well, but what I found most interesting was, 'Men showed a slightly wider variability in words uttered, and boasted both the most economical speaker (roughly 500 words daily) and the most verbose yapping at a whopping 47,000 words a day.'
Of course, what was interesting wasn't that these were both men, I think this study shows that gender is relatively insignificant on this particular point, but what are the differences that created this variation? Are they Psychological or Genetic? Are they effected by social status, family position, etc.? Interesting study but the scope was far too narrow to provide any truly interesting data and insights into the human animal.