• Neuroticism

  Neurotic bloggers tend to use tons of first-person pronouns, fixate on their feelings, employ modifiers such as "awful" and "terribly," and sprinkle the word "stress" throughout their prose, Yarkoni says. Internet celebrity Julia Allison appears to have a penchant for airing the negative.

  "HELP!!!! I have horrible, awful, no good, very bad PMS!" —Julia Allison, November 2, 2007

• Gregariousness

  Gregarious people commonly employ terms indicative of a vibrant social life: "friends," "girls," "tickets," and "drinks" among them. The political pundit, socialite, and founder of The Huffington Post seems to fit the bill.

  "I have been friends with Brenner for thirty years—I can't swear that she danced at my wedding, but she definitely attended it." —Arianna Huffington, March 13, 2006

• Self-Discipline

  A task-oriented mentality is strongly associated with the words "practical," "ready," and "completed." Self-disciplined bloggers are also less likely to take angry or tentative tones. Conservative commentator Andrew Sullivan's style and word choice may reveal a straightand- narrow mindset.

  "So you have a pracitcal, targeted measure that seems to have helped abate a deeper recession in the auto industry." —Andrew Sullivan, August 4, 2009

• Liberalism

  Tests have linked liberalism, openness, and intelligence. Yarkoni found that liberal people use longer words, such as "complicated," "particularly," and "literature." And who's more liberal these days than economist and New York Times blogger Paul Krugman?

  "One of the things I find puzzling about the whole oil market discussion is how complicated people seem to make it." —Paul Krugman, May 13, 2008

Covert Characters

We asked PT 's bloggers ( psychologytoday.com/blog ) which personality traits are easiest for people to conceal.

Wrath Under Wraps

"The capacity for evil is, for most people, the easiest to hide. In our culture, rage is so stigmatic and demonized that we conceal it fairly successfully. We try to be too nice ortoo good. Normal anger can fester and tum into toxic resentment, embitterment, hostility, or explosive violence." — Stephen A. Diamond, Ph.D . Evil Deeds: A forensic psychologist on anger. madness. and destructive behavior

Comfortably Quiet

"I see introversion as one of the easiest traits to mask. Most people falsely assume that introverts are withdrawn, verbally inept, and quiet. But over time, introverts can become quite skilled verbally, and when the subject is one that truly interests them, they can be quite talkative—to the point of enthusiastically dominating the conversation." — Leon F. Seltzer, Ph.D. Evolution of the Self: On the paradoxes of personality

Fear of the Mirror

"The capacity to avoid self-knowledge is an easy quality to hide. Since we all share this trait in one form or another, it fades into the background of everyday life. Even people who consciously strive for self-knowledge fool themselves and unconsciously avoid it. We conceal this universal personality feature not only from others, but from ourselves, too." — Steven Reidbord, M.D. Sacramento Street Psychiatry: More than just meds