James Pennebaker is a psychologist who specializes in analyzing how your use of seemingly innocuous words — like “I”, “we”, “he” or “she” — reflects your emotional state. He’s used his technique to study everything from the relationships of top Al-Qaeda members to the complexity of presidential candidates’ speech patterns. I first heard about his stuff because I tried out AnalyzeWords, a web app Pennebaker and his colleagues created that studies your recent tweets and deduces your “emotional style,” “social style” and “thinking style”. (Apparently, according to my recent tweets I’m “depressed”, “personable”, and “in-the-moment.”)

Anyway, I started reading through Pennebaker’s academic papers and hit upon this really fascinating one: The effect of testosterone on word usage.

Pennebaker knew that many studies have linked increased testosterone levels to aggression, negative moods, increased sex drive, and even things like improved
spatial skills and impaired verbal ability. So that got him wondering: Does higher testosterone affect how we use language?

To test this, he found two subjects who were undergoing testosterone-injection therapy: A 60-year-old man who was getting the injections to restore his upper-body strength, and a 28-year-old biological woman who three years into a transgender program to become a man. Pennebaker got writing samples — like email and journal entries — from the subjects before and after the injections.

The results? As Pennebaker wrote in a summary of the study:

Overall, testosterone had the effect of suppressing the participants’ use of non-I pronouns. That is, as testosterone levels dropped in the weeks after the hormone injections, the participants began making more references to other humans … One function of testosterone, then, may be to steer people’s interests away from other people as social beings.

On the one hand, that matches up with traditional claims about increased testosterone — that it makes you into a kind of gently sociopathic, type-A jerk. But the really interesting thing is that Pennebaker did not detect any other big changes in the subjects’ emotional states. “Contrary to commonly held beliefs,” he writes, “changes in testosterone levels were unrelated to linguistic markers of mood state, aggression, sexuality, achievement, and references to perceptual or cognitive processes.” So maybe some of the stereotypes about testosterone need to be revised.

Of course, it remains to be seen if Pennebaker’s findings hold up; with only two subjects, the results are very provisional. If you want to read his paper — “Testosterone as a Social Inhibitor: Two Case Studies of the Effect of
Testosterone Treatment on Language” — it’s online free here.