Knowing yourself

What the Big Five can and can't tell you

The Big Five is a widely used way of describing personality, tested in many countries and languages.1 It's genuinely useful, and it's also more modest than most online quizzes make it sound. Here's what the research supports, and where it runs out.

What the five traits are

The model sorts the many ways people differ into five broad dimensions: extraversion (being talkative and assertive), agreeableness (trusting and cooperative), conscientiousness (organized and reliable), neuroticism (prone to anxiety and moodiness, with emotional stability at the other end), and openness (curious and creative).1 The idea grew out of what's called the lexical approach: the assumption that the differences between people that matter most end up as words in everyday language.1

Each trait is a spectrum, not a box. Calling someone "high in openness" is shorthand for where they tend to sit along that line compared with other people, not a category they belong to.

Stable, but not set in stone

Personality does change across a lifetime. A large review of 92 samples followed over time found that people, on average, grow more assertive, more conscientious and more emotionally stable, especially between about 20 and 40. Openness and social energy tended to rise in adolescence and dip again in old age, while agreeableness shifted mainly later in life.2

A newer and much larger update, published in 2022, mostly agreed. It found that how consistently people keep their place relative to others grows through early life and levels off in young adulthood, with little sign of further increase after 25. The overall average changes across life looked slightly smaller than earlier estimates, but emotional stability rose more steadily than previously thought. Narrow, specific traits were less stable than the five broad ones.3

Change can also happen on purpose, or at least alongside deliberate effort. A review of 207 studies, most of them about therapy, found that trait measures shifted noticeably over interventions averaging about 24 weeks, with emotional stability changing most and extraversion next, and the changes tended to last at follow-up.4 Most of those studies were in clinical settings, so it's a hopeful finding rather than a promise about any particular self-help plan.

What the traits predict, modestly

Traits do relate to real life. A well-known review of long-term studies found that the links between personality and three big outcomes (how long people live, whether they divorce, and how far they get in their careers) were about as large as the links for socioeconomic status or for cognitive ability.5

But "as large as" doesn't mean large. The same review described personality effects as small to medium. For divorce, for example, higher neuroticism, lower agreeableness and lower conscientiousness were each linked to greater risk, with correlations in the range of about 0.13 to 0.18.5 Links of that size show up as patterns across thousands of people. They say very little about what will happen to any one person or couple.

The good news is that these patterns mostly hold up. In 2019 a psychologist re-tested 78 published links between traits and life outcomes using preregistered studies with large samples. Most (87%) came out in the expected direction, but the effects were typically only about three quarters as strong as first reported.6 Real, then, and a bit smaller than the original headlines.

Relationships follow the same pattern. In large national samples of married couples from Australia, the UK and Germany, a person's own personality accounted for roughly 6% of the differences in how satisfied they were with their relationship. Their partner's personality accounted for 1 to 3%, and how similar the two were added less than half a percent.7 Most of what makes a relationship feel good lies outside what a personality test measures.

Where the model runs out

The five-factor structure isn't as universal as it's sometimes presented. When researchers gave a translated Big Five questionnaire to 632 Tsimane adults, forager-farmers in the Bolivian Amazon, the five factors didn't cleanly appear. Instead, answers grouped into two broad dimensions, roughly being helpful to others and being hard-working.1 The Big Five may partly reflect the kinds of societies where most of the research has been done.

There are everyday limits too. Most Big Five measures ask you to describe yourself, so they capture how you see yourself, which isn't always how you act. Traits describe tendencies averaged over many situations, not what you'll do on a particular Tuesday. And no trait score can tell you whether a specific person is right for you.

A kinder way to use it

The Big Five works best as a shared vocabulary: a way to notice your own patterns, talk about them with people you care about, and remember that they can shift. If you use any app to reflect on your tendencies, including ours, treat what you see as a starting point for a conversation, not a label or a verdict.

This article is general information, not advice. BrainMatch isn't built on or validated by these studies. We simply want to share what's known, including how much isn't.

Sources

  1. Gurven, M., von Rueden, C., Massenkoff, M., Kaplan, H., & Lero Vie, M. (2013). How universal is the Big Five? Testing the five-factor model of personality variation among forager-farmers in the Bolivian Amazon. Journal of Personality and Social Psychology, 104(2), 354–370. https://pmc.ncbi.nlm.nih.gov/articles/PMC4104167/
  2. 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. https://doi.org/10.1037/0033-2909.132.1.1
  3. Bleidorn, W., Schwaba, T., Zheng, A., Hopwood, C. J., Sosa, S. S., Roberts, B. W., & Briley, D. A. (2022). Personality stability and change: A meta-analysis of longitudinal studies. Psychological Bulletin, 148(7–8), 588–619. https://doi.org/10.1037/bul0000365
  4. Roberts, B. W., Luo, J., Briley, D. A., Chow, P. I., Su, R., & Hill, P. L. (2017). A systematic review of personality trait change through intervention. Psychological Bulletin, 143(2), 117–141. https://doi.org/10.1037/bul0000088
  5. Roberts, B. W., Kuncel, N. R., Shiner, R., Caspi, A., & Goldberg, L. R. (2007). The power of personality: The comparative validity of personality traits, socioeconomic status, and cognitive ability for predicting important life outcomes. Perspectives on Psychological Science, 2(4), 313–345. https://pmc.ncbi.nlm.nih.gov/articles/PMC4499872/
  6. 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. https://doi.org/10.1177/0956797619831612
  7. Dyrenforth, P. S., Kashy, D. A., Donnellan, M. B., & Lucas, R. E. (2010). Predicting relationship and life satisfaction from personality in nationally representative samples from three countries: The relative importance of actor, partner, and similarity effects. Journal of Personality and Social Psychology, 99(4), 690–702. https://doi.org/10.1037/a0020385