Are Extroverts Happier?

From WSJ.com:

Extroverts, those outgoing, gregarious types who wear their personalities on their sleeve, are generally happier, studies show. Some research also has found that introverts, who are more withdrawn in nature, will feel a greater sense of happiness if they act extroverted. 

Experts aren't entirely sure why behaving like an extrovert makes people feel better. One theory is that being talkative and engaging influences how people respond to you, especially if that response is positive. Others speculate that people get more satisfaction when they express their core self and opinions. Another possibility: Happiness might come simply from having successfully completed a goal, such as giving a speech. 

... 

Dr. Fleeson, of Wake Forest University, reported in a 2012 article in the Journal of Personality the results of an experiment that found introverts experience greater levels of happiness when they act more extroverted. In the weeklong study, researchers followed 85 people who recorded on Palm Pilots how extroverted they were acting and how happy they were feeling. Other studies of introvert behavior have reached similar conclusions. 

I take issue with the methods of this study. How can you accurately measure the happiness of people in the year 2012 who have to carry around a Palm Pilot all day? Continuing:

So why don't introverts act like extroverts more often? John Zelenski, a psychologist at Carleton University in Ottawa, and fellow researchers probed that question in an April article in the Journal of Personality and Social Psychology. 

A series of studies, which included more than 600 college students, found that introverts misjudge how they would feel after acting extroverted. They often predicted feelings of anxiety and embarrassment, which never transpired.

I'm suspicious of any study that purports to measure or explain "happiness." I think that my concept of happiness is different enough from, say, Anthony Weiner's or Amanda Bynes' (just to pull a couplea' names at random) that you shouldn't really classify them as the same thing.

But I am intrigued by the line, "introverts misjudge how they would feel after acting extroverted." Is that really what introversion is? Social pessimism? I'm not sure I buy that, because I'm a pretty optimistic person, but I'm also about as introverted as you can get. Any other optimistic introverts out there?