Introversion [in-truh-vur-zhuhn] and Extroversion [ek-struh-vur-zhuhn] are terms popularized by Carl Jung in the 1920s to describes how a person gets energy from the world: introverts get energy from inside themselves (ideas and concepts in their own minds), and extroverts get energy from outside of themselves (interacting with other people).
The former can appear quiet and shy, and the latter loud and sociable; however, everyone has some parts of both traits in them, though one will usually dominate over the other. At one time, extroverts were thought to make up almost three-fourths of American society. Now, researchers typically assume that the number of extroverts is pretty much equal to the number of introverts in the country. Virtually all comprehensive models of personality include these concepts in various forms.
Extroversion and introversion are typically viewed as a single continuum. Thus, to be high on one it is necessary to be low on the other. Rather than focusing on interpersonal behavior, however, Jung defined introversion as an ‘attitude-type characterized by orientation in life through subjective psychic contents’ (focus on one’s inner psychic activity); and extroversion as ‘an attitude type characterized by concentration of interest on the external object,’ (the outside world). In any case, people fluctuate in their behavior all the time, and even extreme introverts and extroverts do not always act according to their type.
Extroversion is ‘the act, state, or habit of being predominantly concerned with and obtaining gratification from what is outside the self.’ Extroverts tend to enjoy human interactions and to be enthusiastic, talkative, assertive, and gregarious. They take pleasure in activities that involve large social gatherings, such as parties, community activities, public demonstrations, and business or political groups. Politics, teaching, sales, managing and brokering are fields that favor extroversion. An extroverted person is likely to enjoy time spent with people and find less reward in time spent alone. They tend to be energized when around other people, and they are more prone to boredom when they are by themselves.
Introversion is ‘the state of or tendency toward being wholly or predominantly concerned with and interested in one’s own mental life.’ Some popular writers have characterized introverts as people whose energy tends to expand through reflection and dwindle during interaction. This is similar to Jung’s view, although he focused on psychic energy rather than physical energy. Few modern conceptions make this distinction. The common modern perception is that introverts tend to be more reserved and less outspoken in groups. They often take pleasure in solitary activities such as reading, writing, using computers, hiking, and fishing. The archetypal artist, writer, sculptor, engineer, composer, and inventor are all highly introverted.
An introvert is likely to enjoy time spent alone and find less reward in time spent with large groups of people, though he or she may enjoy interactions with close friends. Trust is usually an issue of significance: a virtue of utmost importance to an introvert choosing a worthy companion. They prefer to concentrate on a single activity at a time and like to observe situations before they participate. They are more analytical before speaking. Introverts are easily overwhelmed by too much stimulation from social gatherings and engagement, introversion having even been defined by some in terms of a preference for a quiet, more minimally stimulating environment. Introversion is not seen as being identical to shy or to being a social outcast. Introverts prefer solitary activities over social ones, whereas shy people (who may be extroverts at heart) avoid social encounters out of fear, and the social outcast has little choice in the matter of his or her solitude.
Although many people view being introverted or extroverted as a question with only two possible answers, most contemporary trait theories measure levels of extroversion-introversion as part of a single, continuous dimension of personality, with some scores near one end, and others near the half-way mark. Ambiversion is a term used to describe people who fall more or less directly in the middle and exhibit tendencies of both groups. An ambivert is normally comfortable with groups and enjoys social interaction, but also relishes time alone and away from the crowd.
Assessing extroversion and introversion is normally accomplished through self-reporting. A questionnaire might ask if the test-taker agrees or disagrees with statements such as, ‘I am the life of the party,’ or ‘I think before I talk.’ Self-report questionnaires have obvious limitations in that people may misrepresent themselves either intentionally or through lack of self-knowledge. As such, it is also common to use peer reporting or third-party observation. Another approach is to present test takers with various sets of adjectives (e.g., thoughtful, talkative, energetic, independent) and ask which describes them most and least. Psychological measures of this trait may break it down into subfactors including warmth, affiliation, positive affect, excitement seeking, and assertiveness/dominance seeking.
British psychologist Hans Eysenck described extroversion-introversion as the degree to which a person is outgoing and interactive with other people. These behavioral differences are presumed to be the result of underlying differences in brain physiology. Extroverts seek excitement and social activity in an effort to heighten their arousal level, whereas introverts tend to avoid social situations in an effort to keep such arousal to a minimum. Eysenck designated extroversion as one of three major traits in his P-E-N model of personality, which also includes psychoticism and neuroticism. Eysenck originally suggested that extroversion was a combination of two major tendencies, impulsiveness and sociability. He later added several other more specific traits, namely liveliness, activity level, and excitability. These traits are further linked in his personality hierarchy to even more specific habitual responses, such as partying on the weekend.
Eysenck proposed that extroversion was caused by variability in cortical arousal. He hypothesized that introverts are characterized by higher levels of activity than extroverts and so are chronically more cortically aroused than extroverts. The fact that extroverts require more external stimulation than introverts has been interpreted as evidence for this hypothesis. Other evidence of the ‘stimulation’ hypothesis is that introverts salivate more than extroverts in response to a drop of lemon juice. Extroversion has been linked to higher sensitivity of the mesolimbic dopamine system to potentially rewarding stimuli. This in part explains the high levels of positive affect found in extroverts, since they will more intensely feel the excitement of a potential reward. One consequence of this is that extroverts can more easily learn the contingencies for positive reinforcement, since the reward itself is experienced as greater.
One study found that introverts have more blood flow in the frontal lobes of their brain and the anterior or frontal thalamus, which are areas dealing with internal processing, such as planning and problem solving. Extroverts have more blood flow in the anterior cingulate gyrus, temporal lobes, and posterior thalamus, which are involved in sensory and emotional experience. This study and other research indicates that introversion-extroversion is related to individual differences in brain function.
Extroverts and introverts have a variety of behavioral differences. According to one study, extroverts tend to wear more decorative clothing, whereas introverts prefer practical, comfortable clothes. Extroverts are likely to prefer more upbeat, conventional, and energetic music than introverts. Personality also influences how people arrange their work areas. In general, extroverts decorate their offices more, keep their doors open, keep extra chairs nearby, and are more likely to put dishes of candy on their desks. These are attempts to invite co-workers and encourage interaction. Introverts, in contrast, decorate less and tend to arrange their workspace to discourage social interaction.
Although extroverts and introverts have real personality and behavior differences, it is important to avoid pigeonholing or stereotyping by personality. Humans are complex and unique, and because extroversion varies along a continuum, they may have a mixture of both orientations. A person who acts introverted in one scenario may act extroverted in another, and people can learn to act ‘against type’ in certain situations. Jung’s theory states that when someone’s primary function is extroverted, his secondary function is always introverted (and vice versa). Acknowledging that introversion and extroversion are normal variants of behavior can help in self-acceptance and understanding of others. For example, an extrovert can accept her introverted partner’s need for space, while an introvert can acknowledge his extroverted partner’s need for social interaction.
Researchers have found a correlation between extroversion and happiness. That is, more extroverted people tend to report higher levels of happiness than introverts. Other research has shown that being instructed to act in an extroverted manner leads to increases in positive affect, even for people who are trait-level introverts. This does not mean that introverts are unhappy. Extroverts simply report experiencing more positive emotions, whereas introverts tend to be closer to neutral. This may be due to the fact that extroversion is socially preferable in Western culture and thus introverts feel less desirable. In addition to the research on happiness, other studies have found that extroverts tend to report higher levels of self-esteem than introverts. Others suggest that such results reflect socio-cultural bias in the survey itself. Also, according to Jung, introverts acknowledge more readily their psychological needs and problems, whereas extroverts tend to be oblivious to them because they focus more on the outer world.
Extroversion is perceived as socially desirable in Western culture, but it is not always an advantage. For example, extroverted youths are more likely to engage in delinquent behavior. Conversely, while introversion is perceived as less socially desirable, it is strongly associated with positive traits such as intelligence and ‘giftedness.’ For many years, researchers have found that introverts tend to be more successful in academic environments, which extroverts may find boring.
It is asserted that Americans live in an ‘extroverted society’ that rewards extrovert behavior and rejects introversion. Other cultures, such as Central Europe, Japan, or regions where Buddhism, Sufism etc. prevail, prize introversion. These cultural differences predict individuals’ happiness such that people who score higher in extroversion are happier, on average, in particularly extroverted cultures and vice versa. Researchers have found that people who live on islands tend to be less extroverted (more introverted) than those living on the mainland, and that people whose ancestors had inhabited the island for twenty generations tend to be less extroverted than more recent arrivals.
Furthermore, people who emigrate from islands to the mainland tend to be more extroverted than people that stay on islands, and those that immigrate to islands. In the United States, researchers have found that people living in the midwestern states of North Dakota, South Dakota, Nebraska, Minnesota, Wisconsin, and Illinois score higher than the U.S. average on extroversion. Utah and the southeastern states of Florida and Georgia also score high on this personality trait. The most introverted states in the United States are Maryland, New Hampshire, Alaska, Washington, Oregon and Vermont. People who live in the northwestern states of Idaho, Montana, and Wyoming are also relatively introverted.