From Jung to the Big Five: what the words mean
The terms come from the Swiss psychiatrist Carl Jung, who in Psychological Types (1921) described introverts as turned towards their inner world of thoughts and feelings, and extraverts as turned towards the outer world of people and things. Jung saw these as attitudes everyone has, with one usually dominant.
The British psychologist Hans Eysenck turned the idea into a measurable dimension in the 1940s to 1960s. He proposed that introverts have a higher baseline level of brain arousal, so they reach their comfortable level with less outside stimulation, while extraverts seek more stimulation to feel alert (Eysenck, 1967). The details of the arousal theory are still debated, but the dimension itself has held up in almost every personality model since.
Today the standard description is the Big Five trait of extraversion (see personality traits). In the widely used model of Costa and McCrae it has six facets: warmth, gregariousness, assertiveness, activity, excitement-seeking and positive emotions. Introversion is simply a low score on this trait. It is not a separate trait, and it is not the same as shyness.
The difference between introverts and extroverts
| Typical introvert | Typical extrovert |
|---|---|
| Recharges alone or with one or two close people | Recharges in company |
| Prefers depth: fewer, longer conversations | Prefers breadth: many contacts, quick exchanges |
| Thinks before speaking | Thinks by talking |
| Finds loud, crowded settings tiring sooner | Finds quiet, solitary settings dull sooner |
| Reports positive emotion as calm and contentment | Reports positive emotion as excitement and enthusiasm |
Two misunderstandings are common. Introverts are not necessarily shy: shyness is anxiety about social judgement, which is linked more to Neuroticism than to extraversion. A confident introvert can give a speech well and simply prefer a quiet evening afterwards. And extroverts are not necessarily shallow or loud; extraversion is about where you draw energy and how much stimulation you enjoy.
Signs you lean one way or the other
These everyday signs are useful for reflection, though only a test that combines many items can place you reliably:
- After a long party or conference day, do you feel drained and want to be alone, or buzzing and keen to carry on?
- When something good happens, is your first impulse to tell people or to enjoy it quietly?
- Do you work out what you think by talking it through, or by thinking it through first?
- In a new group, do you speak early or wait until you have a feel for the room?
- Does a weekend with no plans sound like a relief or like boredom?
Answers that point both ways are normal. Studies that track people through their days find that everyone acts in an extraverted way some of the time and an introverted way at other times; the trait describes the average, not every moment (Fleeson, 2001).
Ambiverts: why most people are in the middle
Scores on extraversion follow a roughly bell-shaped distribution, so most people are neither strong introverts nor strong extroverts. The word ambivert, for this middle group, dates back to the 1920s. It is not a separate type; it is the middle of the same scale.
The middle can have advantages. In a study of call-centre sales staff, Adam Grant (2013) found that people with moderate extraversion scores sold more than either strong introverts or strong extroverts, possibly because they could both listen and push when needed. The finding is from one setting and should not be overstated, but it fits a broader point: neither end of the trait is better overall. Extraversion is linked with more frequent positive emotion (Lucas and Fujita, 2000), while introversion is linked with comfort in focused, independent work.
Is it fixed? Genes, age and change
Twin studies typically estimate that around 40 to 50% of the differences between people in extraversion are linked to genetic differences, in line with a meta-analysis that put the average heritability of personality at about 40% (Vukasović and Bratko, 2015). The rest reflects life experience, and the trait is not fixed. On average, people become slightly less excitement-seeking and gregarious from young adulthood into middle age, while social confidence tends to increase (Roberts, Walton and Viechtbauer, 2006). Within that broad stability, people can and do build skills that do not come naturally, such as public speaking for an introvert or solitary concentration for an extrovert.
To see where you sit on the full trait, rather than a single yes or no, take our Big Five test, which is modelled on the five-trait framework and reports extraversion as a position on a scale. The 16-type model uses the same idea as its first letter, E or I.
Sources
- Jung, C. G. (1921). Psychologische Typen. Rascher. English edition: Psychological Types (1923). Kegan Paul.
- Eysenck, H. J. (1967). The Biological Basis of Personality. Charles C. Thomas.
- Costa, P. T. and McCrae, R. R. (1992). NEO PI-R Professional Manual. Psychological Assessment Resources.
- Fleeson, W. (2001). Toward a structure- and process-integrated view of personality. Journal of Personality and Social Psychology.
- Lucas, R. E. and Fujita, F. (2000). Factors influencing the relation between extraversion and pleasant affect. Journal of Personality and Social Psychology.
- Grant, A. M. (2013). Rethinking the extraverted sales ideal: the ambivert advantage. Psychological Science.
- Vukasović, T. and Bratko, D. (2015). Heritability of personality: a meta-analysis of behavior genetic studies. Psychological Bulletin.
- Roberts, B. W., Walton, K. E. and Viechtbauer, W. (2006). Patterns of mean-level change in personality traits across the life course. Psychological Bulletin.
Frequently asked questions
what is an introvert and extrovert
An introvert prefers calmer settings and recharges alone; an extrovert seeks company and stimulation and is energised by it. Psychologists treat these as the two ends of one trait, extraversion, rather than two kinds of people.
what's the difference between extrovert and introvert
The core difference is how much social stimulation feels comfortable and where you draw energy from. Extroverts tend to enjoy many contacts and think out loud; introverts tend to prefer fewer, deeper conversations and think before speaking. Neither is more able or more sociable in any fixed sense.
What does it mean to be an introvert?
It means scoring low on extraversion: you tend to find busy social settings tiring sooner and enjoy quiet time to recharge. It does not mean you dislike people, and it is different from shyness, which is about fear of judgement.
Is introvert the same as omnivert?
No. Omnivert is a popular term, not a research one, for someone who swings between strongly introverted and strongly extraverted behaviour depending on mood or situation. In trait research everyone varies from moment to moment; your trait score describes your average.
Is introversion a genetic trait?
Partly. Twin studies put the heritability of extraversion at roughly 40 to 50%, similar to other personality traits. The rest comes from experience, and no single gene decides it.
What are introverts good at?
On average, introverts are comfortable with sustained, focused work, listening, and one-to-one conversation, and they tend to think before acting. These are tendencies, not guarantees; skill depends much more on practice than on where you sit on the trait.
What jobs are good for introverts?
Roles with time for independent, focused work often suit introverts, for example research, writing, programming, design, analysis or skilled trades. But introverts succeed in teaching, sales and leadership too. A career interest test usually says more about fit than extraversion alone.
Can introverts fall in love?
Yes. Introversion affects how much social stimulation someone enjoys, not their capacity for affection or attachment. Many introverts prefer a small number of close relationships and invest deeply in them.