Personality Test Accuracy

Updated October 6, 2022 by BetterHelp Editorial Team

Taking a personality test has been a popular way to give us some insight into an individual’s character traits. It has been used informally for fun, to help psychologists and therapists in addressing clients’ needs, and by organizations to assess prospective employees as well as current ones, especially for leadership qualities. This article will go over what a psychology personality test entails and explain where they are effective as well as some of their pitfalls.

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What Is A Personality Test?

A personality test is a typically a self-report (meaning no interference from a researcher) questionnaire that measures personality traits, such as introversion and extraversion.

There are several different personality test types available, and you may have heard of some of these:

  • Myers-Briggs Type Indicator
  • DISC Assessment
  • Winslow
  • Hexaco
  • Big Five (also known as the Five-Factor model)

While these tests have similar goals in mind, they do measure different criteria, and some have been more preferential in specific scenarios.

However, the most famous personality test is the Myers-Briggs Type Indicator (MBTI), and it has been widely distributed across various capacities, and it’s also often taken casually by people who are curious about what their results are.

It’s also the personality test that's one of the oldest available and it was created in the 1940s by Isabel Briggs-Myer and her mother, Katherine Briggs, who was influenced by Carl Jung’s publication Psychological Type. [1]

The MBTI personality test consists of 93 questions, takes just under 30 minutes to complete, and is designed to measure these four specific criteria [1] [2]:

  • Introversion (I) vs. Extraversion (E): where people prefer to focus their attention and energy
  • Sensing (S) vs. Intuition (N): how people absorb information
  • Thinking (T) vs. Feeling (F): how people make their decisions and what they base them on
  • Judgment (J) vs. Perception (P): how people orient themselves to the rest of the world

At the end of the personality test, the participant will be given a result, usually something along the lines of INFJ, ESFP, etc. The letters, which correspond to a psychological dimension, indicate one’s dominance towards a trait, which is known as primary preference. In total, there are 16 unique personality types in the Myers-Briggs model, and while some may some dimensions, each one is said to correspond to an entirely different person. [3]

Other personality tests, like the DISC personality test, which measures Dominance, Influence, Steadiness, and Conscientiousness, groups its participants into only these four different types. For example, a D-type personality is a person who is direct, assertive, and driven, whereas an S-type is regarded as sympathetic, reserved, and patient.

As mentioned before, regardless of what metrics are being considered, these tests try to give us a clearer picture of what our personalities are like by attaching a label to them. These labels can also provide insight into what jobs and organizational positions a person might excel at; however, their validity and accuracy have been called into question over the years.

Is A Personality Test Reliable?

Millions of people worldwide take some kind of personality test daily for a variety of different purposes, but do the results give us the best representation of who we are? This section will go over some of the primary criticisms of these assessments and provide statistics that demonstrate where they may be unreliable.

Because the MBTI is the most widely used and researched of all the personality tests, most of the issues here will reference that specific psychological assessment.

One of the main faults that people have with such tests is addressing those who may fall in-between categories. Essentially, it is believed that these tests are too black-and-white, with no gray area.

For example, the personality test might list two different people as introverted and extraverted, respectively, but their answers might be quite similar overall. Research data suggests that most people score in between the extremes, despite the personality test producing a polarizing result [3].

For example, if one person takes the MBTI personality test and barely reaches the threshold of being classified as introverted, and another individual score enough to be extraverted, they will be labeled with I and E, respectively, despite answering most questions similarly.

Another issue is that people’s results can change in a very short period. To test reliability, people should take a personality test at least twice. This is called test-retest reliability and can be carried out several weeks after the initial personality test.

Because personality types are supposed to be concrete, one would expect to receive the same result every single time. It is possible to, but studies suggest that in as little as five weeks from the first personality test, 50 percent will be given a new personality type their second time around. [3]

Importantly, there isn’t any positive indicator that a personality score corresponds with occupational roles and success within them. In fact, there is no evidence that people can be grouped into specific categories, such as the 16 types in the MBTI. [3]

Should A Personality Test Be Used in Professional & Academic Environments?

Since there is little to no supporting evidence that people can accurately be placed into personality types, this calls into question whether they should be used as much as they have been.

Because of its ease of use, it has been used in many different sectors, but the Army Research Institute has determined that it should not be used for career counseling [3].

Aside from having questionable accuracy, another proposed reason for this is that it has the potential to be misused by people in power (i.e., a hiring manager). Such individuals may come to believe that certain people are suitable for a job and only hire based on prospective employee’s personality type rather than experience and credentials.

For example, they might determine that only introverted types are the best for administrative positions, such as accountants, and that extraverts are ideal for sales, ruling out introverts for those jobs.

It’s also possible that employees may also use personality typing to justify not cooperating with others or following certain directions.

However, the official Myers-Briggs website states in response to many of its criticisms that it was never designed to “measure aptitude or predict performance.” What it is effective at is identifying styles of learning which can guide students on a career path that they can resonate with. It can also assist in areas such as stress management and team building. [2]

Even other psychological personality tests like the Big Five, which measures somewhat similar parameters as the MBTI, can create some biases. For example, if someone scores high on Neuroticism but low on Extraversion and Openness, depending on the person involved in a selection process, they might skip over a candidate based solely on these traits.

Therefore, because personality tests may not be the most reliable way to describe a person completely, they should be used with caution, but not eliminated from use in schools and businesses. They shouldn’t be involved in admissions and hiring processes, but personality tests can be a tool for assistance by giving insights into how people learn and communicate best.


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Psychological personality tests do have appropriate uses, but based on statistical research, it’s determined that they may not be the most reliable and accurate means of illustrating a person’s entire personality.

Nonetheless, they are one of the only ways of doing so, and they do have value, albeit overestimated sometimes.

One of the most important aspects of these assessments is their ability to get people to wonder why they and others think and behave the way they do and paves the way for discussion about personality differences [2].

This is evident with the MBTI’s popularity; people casually take the personality test and the results with their friends because the subject is interesting and opens the potential to learn about others.

While these tests can be beneficial in some scenarios, they sometimes should be taken with a grain of salt, and their application should be limited. As mentioned before, they should never be used to make critical decisions such as hiring someone a job. Those should be determined by qualifications, like grades, and relevant skills and experience.

Tests like the MBTI can only describe and not predict behavior; therefore, it cannot determine how someone will perform [2]. Because of some of the uncertainty that a psychological personality test can create, the best possible use of them should be used to learn about others and make them feel included, rather than exclude others based on potentially inaccurate results.

Importantly, people cannot be perfectly placed into distinct boxes that a personality test creates. There are too much complexity and uniqueness amongst people, and the likelihood of having an in-between score is quite high. Human behavior is very dynamic, and it has the potential to fluctuate, especially based on certain situations, and illustrating that is where many of these assessments fall short.


Yang, C., Richard, G., & Durkin, M. (2016). The association between Myers-Briggs Type Indicator and Psychiatry as the specialty choice. International Journal of Medical Education, 7, 48-51. doi:10.5116/ijme.5698.e2cd

Thompson, R. (2016, December 14). Using the MBTI in Education in the Way It Was Designed. Retrieved April 23, 2019, from

Pittenger, D. J., Ph.D. (1993, Fall). Measuring the MBTI… And Coming Up Short. Retrieved April 23, 2019, from

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