It turns out, for example, that men with low-pitched voices have more than the usual amount of testosterone, which makes them unusually assertive.  No surprise that trial lawyers, who make their living by locking verbal horns in front of spectators, have 30 percent more testosterone than other lawyers.

John L. Locke,"Why Do Men and Women Talk Differently?", WSJ Speakeasy, Oct. 19, 2011.