Are Personality Tests Better than Astrology?

It seems so, at least for some things. A study explored whether some popular personality tests (a MBTI-inspired and the Big Five) could predict1 certain life outcomes, comparing these tests against astrology.

While, unsurprisingly, astrology performed no better than random chance, the personality tests had a weak but existing predictive power. The Big Five model was the best, explaining about 6% of the variance in various life outcomes, while the MBTI-inspired explained only 1.2% of the variance. However, for some specific life outcomes, the Big Five was much better. The test could explain up to 32% of the variance for ‘life satisfaction’.

There are some reasons why the MBTI-inspired test was not as good as the Big Five model:

  1. It lacks the ’neuroticism’ factor, which is a moderate predictor of some life events, such as suicidal thinking and the perception of receiving rewards for life achievements.
  2. The study did not use the proprietary MBTI test but an inspired version, so the ’true’ MBTI test might perform better.
  3. The MBTI test uses categorical scales (extroverted vs. introverted) instead of continuous scales, while personality traits generally follow normal rather than bimodal distributions. Thus, labeling someone in the 45th percentile of extroversion as ’extroverted’ doesn’t make much sense.

Here are the regression coefficients for a regression model between the Big Five scales and life outcomes:


Another study reported that conscientiousness and extroversion are correlated with higher salaries. In comparison, high agreeableness is correlated with lower salaries, which aligns with the ‘received awards for my achievements’ finding in the table above.

And now you can start telling your friends to replace astrology with the Big Five, it is not great but at least better =)

  1. By ‘predict’ I mean that life outcomes could be inferred from personality tests. It is also possible that life outcomes influence personality, or that another factor (X) influences both. ↩︎