Personality test accuracy and practical uses

Personality tests can sometimes offer some insight into an individual’s character traits. Some people use them informally for fun, but others are sometimes used to help organizations assess prospective employees as well as current ones, especially for leadership qualities. However, many psychologists view personality tests with some skepticism, with some stating that their validity hasn’t been tested scientifically. 

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History of personality tests

Personality tests began to be developed in the early 20th century. They were sometimes used during World War I as a way to assess whether soldiers were psychologically fit to fly aircraft. Psychologists started creating other personality scales, but their validity was questionable because they may not have measured what their creators purported to measure.

They were developed based on the researchers’ feelings and assumptions about personality. 

Still, some tests developed in the 20th century were used for a variety of purposes. Below, we’ll look at personality tests and what they intend to measure:

What’s in a personality test?

Most personality tests consist of 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:

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

While these tests have similar goals, they measure different criteria, and some may be preferred over others in different contexts.

The Myers-Briggs Type Indicator

One of the most famous personality tests is the Myers-Briggs Type Indicator (MBTI). It has been widely distributed across various fields, but it’s often taken casually by people who are curious about what their results are as well.

Created in the 1940s by Isabel Myers and her mother, Katherine Briggs, the MBTI is one of the oldest personality tests to be used in a professional or therapeutic setting. The MBTI is influenced in part by Carl Jung’s theories of personality type and consists of 93 questions. It takes 15-25 minutes to complete and is designed to measure the following traits:

• 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 receives a result, such as INFJ, ESFP, ESTP, etc. The letters, which correspond to a psychological dimension, indicate one’s dominance toward a trait, which is known as primary preference.

DISC personality test

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

Regardless of which metrics are considered, these tests aim to provide a clearer picture of what a person’s personality is like. While the labels used in these tests may provide insight into what jobs and organizational positions in which a person might excel, their validity and accuracy have been called into question over the years.

Reliability of personality tests

One of the main concerns that people have about personality tests is related to people who may fall in between categories. Some people believe these tests are too black-and-white, with no gray area.

For example, a personality test might list two different people as introverted and extroverted, respectively, but their answers might be quite similar overall.

If one person takes the MBTI and barely reaches the threshold of being classified as introverted, and another person scores high enough to be extroverted, they will be labeled with I and E, respectively, despite answering most questions similarly.

Another concern is that people’s results can change in a very short period. To test reliability, people can take a personality test twice. This may help measure test-retest reliability, and the second test can be carried out several weeks after the initial personality test. 

In terms of practical use, research suggests that a personality score doesn’t necessarily correspond with occupational roles and success within them. Also, people might not be neatly grouped into specific categories, such as the 16 types in the MBTI.

Personality testing in professional and 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 regularly.

Aside from having questionable accuracy, another proposed reason for reducing the use of personality tests is that they have the potential to be misused by people in power (e.g., a hiring manager). Such individuals may come to believe that certain people are suitable for a job and only hire based on prospective employees’ personality test results rather than experience and credentials.

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

Even other psychological personality tests, like the Big Five, which measures somewhat similar parameters as the MBTI, can create some biases. Some researchers say that the Big Five has more validity than other personality tests in that it was developed empirically with peer review and demonstrated consistency in scores. However, it may not be consistent across cultures, and it can also lead to bias in hiring. For example, if someone scores high on Neuroticism but low on Extraversion and Openness, they might not be selected for a job, solely based on their scores. 

Personality tests may not be the most reliable way to describe a person, so they might be used with caution in schools and businesses. While they can create a bias in admissions and hiring processes, personality tests might serve as a tool to provide insights into how people learn and communicate best.

Personality tests as a tool for therapy

Psychological personality tests may have appropriate uses in certain contexts. Perhaps one of the most useful aspects of these assessments is their ability to spur thought and dialogue about why people think and behave the way they do. They can pave the way for discussion about personality differences and provide a helpful label for personality traits to encourage understanding.

Mental health professionals sometimes ask their clients to take a personality test, most commonly the MBTI, to establish a groundwork for discussion. The therapist may explore the results of the test and get input from the client about their thoughts and feelings about the results. They may take an in-depth look at why the results do or do not resonate with the client and use them to illustrate how different personality types may function in relationships, at work, and in day-to-day behaviors.

Each person is unique and possesses nuanced personality traits that often cannot be explained with a simple test result. For this reason, psychologists may exercise caution in how they use personality tests as a tool for therapeutic exploration.