Personality types: what the science says

Personality tests are fun, and they can help you understand yourself. They can also be used to put people in boxes. This page explains which models have strong science behind them, which are mostly for fun, and how to use any of them to feel less alone.

The Big Five: the best-researched model

Psychologists who study personality mostly use the Big Five. It describes personality as five broad traits. Each is a sliding scale, not a type. Nearly everyone lands somewhere in the middle on most of them.

A simple way to remember them is the word "OCEAN".

How each trait can shape connection

None of these is good or bad. Each has strengths and each has a catch.

• Openness. If you are high in openness, new classes, travel groups, art or discussion groups may draw you in. If you are lower, you may connect best through familiar routines: the same café, the same congregation, the same team.
• Conscientiousness. High scorers are often reliable friends who remember birthdays and show up. The catch is overcommitting to work and leaving no time for people. Lower scorers may forget to follow up; calendar reminders help.
• Extraversion. See introverts, extraverts and everyone between. Lower scorers often do best with one-on-one or structured time; higher scorers with lively groups.
• Agreeableness. High scorers are often kind and easy to be around, but can say yes to everything and end up drained or taken for granted. Lower scorers may come across as blunt; a little extra warmth goes a long way.
• Neuroticism. People higher in this trait feel worry, hurt and rejection more strongly. That can make reaching out feel risky. It also often comes with deep empathy. If worry is getting in the way, see social anxiety and shyness and the loneliness trap.

A 2020 review of 113Studies pooled in a 2020 meta-analysis of loneliness and the Big Five traits (Buecker and colleagues)As of March 13, 2020.The studies included more than 93,000 people. The links were moderate and correlational: they do not show that personality causes loneliness.Source: European Journal of Personality blog: Press release, Loneliness and the Big Five personality traits: A meta-analysis studies found that loneliness was most strongly linked with higher neuroticism and lower extraversion, and less strongly with lower agreeableness and conscientiousness. These links were moderate. They do not mean personality causes loneliness; loneliness can also change how people describe themselves. And many people with these traits are well connected.

Free Big Five tests

These are free as of October 2026. Both use items from the International Personality Item Pool, a public-domain set of personality questions built by researchers.

• Open-Source Psychometrics Project (opens in a new tab): 50 questions, a few minutes. It says answers are recorded anonymously and may be used for research.
• bigfive-test.com (opens in a new tab): 120 questions, about 10 minutes, in many languages. It is free and open-source.

Some free test sites are run by companies that sell other products or show ads. You don't need to give your name, email or phone number to take a Big Five test.

MBTI and the Enneagram

The Myers-Briggs Type Indicator (MBTI) sorts people into 16 four-letter types, like INFJ or ESTP. The Enneagram sorts people into nine numbered types. Both are very popular, and many people find them a useful starting point for talking about themselves.

To be honest and kind about it: their scientific support is much weaker than the Big Five's.

• MBTI. Independent researchers have long raised concerns, including that some people get a different type when they retake it, and that sorting people into two boxes on each scale loses a lot of information, since a person just over the line and a person just under it get different letters. The MBTI's publisher points to its own studies showing more stable results.
• Enneagram. A 2021 review of the research found mixed evidence. Some parts lined up with the Big Five, but studies usually did not find nine separate types, and much of the research was unpublished.

If one of these helped you understand yourself or talk with someone you love, that is real and worthwhile. Just hold the result lightly, and don't use it to decide who you can or can't be friends with. (See finding people you fit with.)

Tendencies, not destiny

Any test describes how you tend to act, on average, today. It does not decide your future.

• Personality can shift. Traits are fairly steady, but they are not frozen. Age, life events and new habits can all move them a little over the years.
• Behavior is a choice. A quiet person can learn to start conversations. A worrier can learn to reach out anyway.
• Context matters. You may be bold with old friends and shy with strangers. Both are you.

What to avoid

• Paying for "premium" reports you don't need. The free results are enough to start.
• Labeling others. "She's a Type 8, so she'll never..." is unfair to a real, changing person.
• Using a type to excuse hurting people. A trait explains, it doesn't excuse.