Big five personality traits explained

Here are the big five personality traits explained in one line: five broad ways in which people differ, called openness, conscientiousness, extraversion, agreeableness and neuroticism. Researchers agree on them because the same five turn up again and again: in the words people use to describe each other^[1], in ratings by friends as well as by people themselves^[2], and in 50 cultures around the world^[3]. About 40% of the differences between people in these traits are linked to genes, by a large review of twin and family studies^[4].

Take the Big Five personality test

The five traits in plain words

Openness: curiosity, imagination and liking for new ideas, art and experiences.
Conscientiousness: being organised, careful, reliable and keen to finish what you start.
Extraversion: enjoying company, talking, energy and excitement.
Agreeableness: trust, warmth, kindness and willingness to cooperate.
Neuroticism: how easily you feel worry, sadness or stress; its opposite is emotional stability.

Each trait is a scale, not a box. Most people sit somewhere near the middle of each, and no point on a scale is the right one to have. None of the five is a measure of how good or clever a person is.

The research in one table

Key findings behind the five factor model
Question	What a study found
Do the five show up in everyday words?	1,431 trait adjectives gave the same five factors in 10 different analyses
Do others see the same traits?	Self-ratings agreed with friends' ratings at 0.25 to 0.62
Do they hold across cultures?	The structure was recognisable in all 50 cultures studied
Are they inherited?	About 40% of the differences linked to genes, 60% to environment
Are they stable?	Year-to-year consistency rose from 0.31 in childhood to about 0.74 between 50 and 70
Do they predict life outcomes?	87% of 78 published links were found again

Where the five came from

The idea started with language. If a way in which people differ matters, people will have a word for it. Researchers collected the adjectives of English that describe people, asked many people to rate themselves or others on them, and looked for the groups the words fell into. In a set of studies published in 1990, Lewis Goldberg analysed 1,431 trait adjectives grouped into 75 clusters and found the same five factors in 10 different analyses. No factor beyond the fifth held up across his samples^[1].

Questionnaire researchers reached the same five from another direction. In a study published in 1987, Robert McCrae and Paul Costa compared 738 ratings by friends of 275 adults with those adults' own answers. The five factors appeared in both, and what people said about themselves agreed with what others said about them, with correlations of 0.25 to 0.62^[2]. A trait that others can see is more than a self-image.

The same five around the world

If the five were an accident of English or of American students, they would not travel. In a project published in 2005, students in 50 cultures each rated someone they knew well, 11,985 people in all, on the same questionnaire translated into their language. The five-factor structure was clearly repeated in most cultures and recognisable in all of them^[3].

The same project found that age differences followed the pattern seen in self-reports, with moderate change during the college years and slower change after about 40^[3].

Nature, nurture and change

Twin, family and adoption studies estimate how much of the difference between people is linked to genes. A review published in 2015 pooled 62 results from more than 100,000 people. On average about 40% of the differences in personality were linked to genetic and 60% to environmental influences. Twin studies gave higher estimates (0.47) than family and adoption studies (0.22)^[4]. That is about differences within a group, not about how much of one person's character came from their parents.

Personality is fairly stable, and grows more so with age. A review of 152 long-term studies, published in 2000, measured how well people kept their place relative to others over about 6.7 years. The consistency rose from 0.31 in childhood to 0.54 in the college years, 0.64 at age 30 and a plateau around 0.74 between 50 and 70^[5].

Stable does not mean fixed. A second review, of 92 samples followed over time, found that people on average become more conscientious and more emotionally stable, especially between 20 and 40, while openness rises in adolescence and falls in old age, and agreeableness changes only in old age^[6].

Broad traits and narrow facets

Each of the five is broad, and is usually split into narrower facets. The questionnaire our Big Five test uses divides every trait into six facets of four statements each: extraversion, for example, covers friendliness, liking for company, assertiveness, activity, seeking excitement and cheerfulness. Two people with the same extraversion score can get there by different routes, one through cheerfulness, the other through assertiveness, which is why a full profile shows the facets as well as the five totals.

The five are also not types. A score is a place on a scale shared by everyone, not a group you belong to; most people are near the middle on several traits at once.

Do the traits predict anything?

Studies have linked the five to dozens of outcomes, from relationships to work. Psychology has had trouble repeating some famous findings, so in 2019 Christopher Soto ran large, preregistered repeats of 78 published links between traits and life outcomes, with a median of 1,504 people each. 87% of the links were found again in the expected direction, though typically at 77% of their original strength^[7].

So the traits do tell you something real about how lives tend to go, on average, across many people. They tell you much less about any single person, and they are no verdict on anyone.

Measuring your own five traits

Our Big Five personality test uses a public-domain questionnaire of 120 statements that measures the five traits and thirty narrower facets. A shorter personality test uses 50 statements, and the quick personality test 10. Longer questionnaires measure more precisely; shorter ones give a quick sketch.

Results are shown on each scale, with the middle marked. Large published samples show how answers spread in one population: for example, 320,128 adults in the United States answered the same 120 statements online^[8]. Answer as you usually are, not as you would like to be, and read the result as a description, not a judgement.

Whether people also fall into types is the subject of what is my personality type?

Questions

What are the big five personality traits?

Openness, conscientiousness, extraversion, agreeableness and neuroticism (the opposite of emotional stability). Each is a scale on which people differ by degree.

Is personality inherited?

Partly. A review of 62 results from twin, family and adoption studies linked about 40% of the differences between people to genes and the rest to environment.

Does personality change with age?

A little, and in a common direction: on average people become more conscientious and emotionally stable through young adulthood. Their place relative to others becomes steadier with age.

Why five traits and not more?

Because five broad factors keep appearing when many descriptions are analysed, and further factors did not hold up across samples. Each of the five can be split into narrower facets.

Sources

Goldberg, L. R. (1990). An alternative "description of personality": The Big-Five factor structure. Journal of Personality and Social Psychology, 59(6), 1216–1229.doi:10.1037/0022-3514.59.6.1216
Abstract: "In the 45 years since Cattell used English trait terms to begin the formulation of his \"description of personality,\" a number of investigators have proposed an alternative structure based on 5 orthogonal factors." "In the first of 3 studies, 1,431 trait adjectives grouped into 75 clusters were analyzed; virtually identical structures emerged in 10 replications, each based on a different factor-analytic procedure." "None of the factors beyond the 5th generalized across the samples." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/2283588/)
McCrae, R. R., & Costa, P. T., Jr. (1987). Validation of the five-factor model of personality across instruments and observers. Journal of Personality and Social Psychology, 52(1), 81–90.doi:10.1037/0022-3514.52.1.81
Adults rated by themselves and by people who knew them
Abstract: "adjective factors of neuroticism, extraversion, openness to experience, agreeableness-antagonism, and conscientiousness-undirectedness were identified in an analysis of 738 peer ratings of 275 adult subjects. Intraclass correlations among raters, ranging from .30 to .65, and correlations between mean peer ratings and self-reports, from .25 to .62, showed substantial cross-observer agreement on all five adjective factors." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/3820081/)
McCrae, R. R., & Terracciano, A. (2005). Universal features of personality traits from the observer's perspective: Data from 50 cultures. Journal of Personality and Social Psychology, 88(3), 547–561.doi:10.1037/0022-3514.88.3.547
Abstract: "To test hypotheses about the universality of personality traits, college students in 50 cultures identified an adult or college-aged man or woman whom they knew well and rated the 11,985 targets using the 3rd-person version of the Revised NEO Personality Inventory. Factor analyses within cultures showed that the normative American self-report structure was clearly replicated in most cultures and was recognizable in all." "Cross-sectional age differences for 3 factors followed the pattern identified in self-reports, with moderate rates of change during college age and slower changes after age 40." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/15740445/)
Vukasović, T., & Bratko, D. (2015). Heritability of personality: A meta-analysis of behavior genetic studies. Psychological Bulletin, 141(4), 769–785.doi:10.1037/bul0000017
Abstract: "the final sample included 62 independent effect sizes, representing more than 100,000 participants of both genders and all ages." "The average effect size was .40, indicating that 40% of individual differences in personality were due to genetic, while 60% are due to environmental influences." "study design was a significant moderator with twin studies showing higher estimates, .47, compared to family and adoption studies, .22." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/25961374/)
Roberts, B. W., & DelVecchio, W. F. (2000). The rank-order consistency of personality traits from childhood to old age: A quantitative review of longitudinal studies. Psychological Bulletin, 126(1), 3–25.doi:10.1037/0033-2909.126.1.3
Abstract: "From 152 longitudinal studies, 3,217 test-retest correlation coefficients were compiled. Meta-analytic estimates of mean population test-retest correlation coefficients showed that trait consistency increased from .31 in childhood to .54 during the college years, to .64 at age 30, and then reached a plateau around .74 between ages 50 and 70 when time interval was held constant at 6.7 years." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/10668348/)
Roberts, B. W., Walton, K. E., & Viechtbauer, W. (2006). Patterns of mean-level change in personality traits across the life course: A meta-analysis of longitudinal studies. Psychological Bulletin, 132(1), 1–25.doi:10.1037/0033-2909.132.1.1
Abstract: "The present study used meta-analytic techniques (number of samples = 92) to determine the patterns of mean-level change in personality traits across the life course. Results showed that people increase in measures of social dominance (a facet of extraversion), conscientiousness, and emotional stability, especially in young adulthood (age 20 to 40). In contrast, people increase on measures of social vitality (a 2nd facet of extraversion) and openness in adolescence but then decrease in both of these domains in old age. Agreeableness changed only in old age." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/16435954/)
Soto, C. J. (2019). How replicable are links between personality traits and consequential life outcomes? The Life Outcomes of Personality Replication Project. Psychological Science, 30(5), 711–727.doi:10.1177/0956797619831612
Abstract: "I conducted preregistered, high-powered (median N = 1,504) replications of 78 previously published trait-outcome associations. Overall, 87% of the replication attempts were statistically significant in the expected direction. The replication effects were typically 77% as strong as the corresponding original effects, which represents a significant decline in effect size." (read on 2026-10-06: https://pubmed.ncbi.nlm.nih.gov/30950321/)
Kajonius, P. J., & Johnson, J. A. (2019). Assessing the structure of the Five Factor Model of Personality (IPIP-NEO-120) in the public domain. Europe's Journal of Psychology, 15(2), 260–275.doi:10.5964/ejop.v15i2.1671
n = 320,128; Volunteers in the United States aged 19 to 69 (mean age 28.1; 60% women) who answered all 120 items on a website
Table A1, "Sample Descriptive Statistics of 5 Trait Domains and 30 Facets" (Trait domain, M, SD): "Neuroticism 11.10 2.66", "Extraversion 13.69 2.36", "Openness 13.71 2.06", "Agreeableness 14.87 2.01", "Conscientiousness 14.95 2.34". Note: "N = 320,128. … The facet trait scales ranged from 4 (Min) to 20 (Max)." Method: "Six facet traits in turn are averaged into one trait factor." (read on 2026-10-06: https://pmc.ncbi.nlm.nih.gov/articles/PMC7871748/)