Personality types and traits glossary
The short answer: a personality trait is a position on a scale that everyone sits somewhere on. A personality type is a category you get sorted into. Trait models measure; type models label. Nearly every argument about personality tests comes down to that distinction.
Twenty-five terms that come up whenever someone asks what type of person you are, defined plainly and without the sales pitch. Each definition stands on its own, so you can quote one without reading the rest (which is the only real test of a definition).
Core concepts
- Personality trait
- A personality trait is a consistent pattern of thinking, feeling and behaving that shows up across situations and stays reasonably stable over years. Traits are measured as positions on a scale rather than as categories you belong to.
- Personality type
- A personality type is a category a person is sorted into, such as one of the sixteen Myers-Briggs codes. Type systems are easier to talk about than traits and less accurate, because they force people near a midpoint into one side of it.
- Trait versus type
- Trait versus type is the distinction underneath nearly every argument about personality tests. A trait model places you on a scale that everyone sits somewhere on; a type model sorts you into a category. Traits measure, types label.
- Retest reliability
- Retest reliability is how consistently an assessment returns the same result for the same unchanged person over time. It is the measure on which type-based instruments perform worst and trait-based instruments perform well.
The Big Five traits
- Big Five
- The Big Five is the personality model with the strongest research support, scoring a person on five continuous dimensions: openness, conscientiousness, extraversion, agreeableness and neuroticism. It produces five numbers rather than a type.
- Openness
- Openness is the Big Five trait describing appetite for new ideas, art, abstraction and untested plans. High scorers seek novelty; low scorers prefer the familiar and the proven.
- Conscientiousness
- Conscientiousness is the Big Five trait describing organisation, reliability and follow-through. It is the trait that rises most consistently with age, and the one most often linked to work performance.
- Extraversion
- Extraversion is the Big Five trait describing where a person's energy comes back from. Extraverts gain energy from stimulation and other people; introverts spend energy on the same activity and recover it in solitude.
- Agreeableness
- Agreeableness is the Big Five trait describing warmth, cooperativeness and how far someone will bend to keep a room comfortable. It is valuable in a team and expensive in a negotiation.
- Neuroticism
- Neuroticism is the Big Five trait describing how strongly negative emotion lands and how long it stays. It is a volume dial rather than a verdict, and Myers-Briggs has no equivalent for it.
The other frameworks
- Myers-Briggs Type Indicator
- The Myers-Briggs Type Indicator is a questionnaire that sorts people into one of sixteen four-letter types using four either-or pairs. Around half of takers get a different type on retest within about five weeks.
- Enneagram
- The Enneagram is a personality system describing nine core types defined by underlying fear and desire rather than by behaviour. It adds wings, growth and stress directions, and levels of development, and has a thin empirical base.
- Type A personality
- Type A personality describes a pattern of time urgency, competitiveness, drive, impatience and hostility under pressure. It came from 1950s cardiology research rather than personality psychology and was never validated as a trait model.
- Type B personality
- Type B personality is the relaxed counterpart to Type A: even-paced, less driven by deadlines, and able to rest without guilt. It was defined mainly as the absence of the Type A pattern.
Effects and findings
- Barnum effect
- The Barnum effect is the tendency to rate vague, broadly positive personality descriptions as highly accurate about oneself specifically. It is the reason horoscopes and name-based quizzes feel more accurate than they have any right to.
- Ambivert
- An ambivert is someone scoring near the middle of the extraversion scale, with traits of both introversion and extraversion depending on the situation. Most people are ambiverts, because extraversion is normally distributed.
- Maturity principle
- The maturity principle is the finding that personality traits drift in a common direction with age: conscientiousness and agreeableness rise while neuroticism declines. The average change is roughly a tenth of a standard deviation per decade.
- Rank-order stability
- Rank-order stability is the tendency for a person's position relative to other people on a trait to stay constant even as everyone's absolute level shifts. It is why personality feels fixed while also measurably changing.
- Name-based personality test
- A name-based personality test returns a personality type from a person's name alone, with no questionnaire. It cannot measure anything about the person, so it is entertainment rather than assessment.
The six everyday types
- The Optimist
- The Optimist is one of the six everyday types used on this site. Assumes it works out and is right often enough to keep assuming it, which is useful in a crisis and exhausting in a budget meeting.
- The Driver
- The Driver is one of the six everyday types used on this site. Decides then moves, preferring the wrong call on Tuesday to the right one in three weeks.
- The Peacemaker
- The Peacemaker is one of the six everyday types used on this site. Reads the room before speaking and usually reads it correctly, which makes them the person everyone tells things to.
- The Observer
- The Observer is one of the six everyday types used on this site. Speaks last and sees most, and is regularly mistaken for shy by people who have not noticed they are being catalogued.
- The Realist
- The Realist is one of the six everyday types used on this site. Wants the actual numbers, and will ask the one question in the meeting that nobody prepared for.
- The Wildcard
- The Wildcard is one of the six everyday types used on this site. Changes the plan at eleven at night, and is the reason half the good stories in a group chat exist.
Frequently asked questions
What is the difference between a personality trait and a personality type?
A trait is a position on a continuous scale that everyone sits somewhere on, such as conscientiousness. A type is a discrete category you get sorted into, such as one of the sixteen Myers-Briggs codes. Trait models measure; type models label.
What are the five personality traits?
Openness, conscientiousness, extraversion, agreeableness and neuroticism. Together they form the Big Five, the personality model with the strongest research support, and each is scored as a position on a scale rather than as a category.
What is the Barnum effect?
The Barnum effect is the tendency to rate vague, broadly positive personality descriptions as highly accurate about oneself specifically. It explains why horoscopes and name-based quizzes feel personal despite containing no information about the reader.
Which personality framework has the most evidence behind it?
The Big Five, by a clear margin. It uses continuous scales, holds up across cultures, and has strong retest stability. Myers-Briggs, the Enneagram and the Type A model all have weaker empirical support.
How many personality types are there?
It depends on the system. Myers-Briggs has sixteen, the Enneagram nine, the A to D model four, and this site uses six everyday types. The Big Five has none at all, because it reports five scores instead of a type.
For the frameworks these terms come from, see the guide to personality types. For the six everyday types in context, the home page has them with illustrations, and the blog goes deeper on each framework.
Vikram Shetty built TrueTst and this site. He writes about personality tests, why people share the results, and where the line sits between a fun answer and a real assessment. More on the about page.