Check out this New York Times book review, a follow-up article, and a PBS interview all about University of Texas social psychologist James W. Pennebaker's new book The Secret Life of Pronouns: What Our Words Say About Us.
I know what you're thinking: "Pronouns? What's next? A book on those little plastic shoelace tips?"
Pennebaker, however, makes the case that pronouns reveal secrets about our modes of consciousness. He spends some time exploring the lyrics of the Beatles, the differences between the sexes, and, in this excerpt from the interview, the ability to predict how college students will perform based on their word choice: