Extraversion and introversion

Introversion and Extroversion, the terms first used by Carl Jung in the 1920's, describe the major way in which a person receives energy from the world. Most people associate introverts with being quiet and shy and extroverts with being loud and sociable. More generally, introverts get energy from inner sources (like ideas and concepts), and extroverts get energy from outer sources (which, based on the common image, are other people).

For the most part, everyone has some parts of both traits in them--though one will still dominate over the other. While at one time, extroverts were thought to make up almost three-fourths of American society, researchers now typically assume that the number of extroverts is pretty much equal to the number of introverts in the country.