Personality Testing—the Good, the Bad, and the Drug-Induced

You know when you take a personality test and you’re deemed “the visionary,” or “the protector,” and then you get a description of your personality characteristics? I’ve noticed that, while the personality characteristics ascribed to me are not bad, they are also the characteristics one would look for in an emotional support dog—loyal, hard-working, caring, easily motivated by food.

Do those words describe me? Yes. Am I annoyed that I have that much in common with a golden retriever? Also, yes.

Maybe that’s why I zeroed in on Lisa Feldman Barrett’s assertion in 7 ½ Lessons About the Brain that the Myers-Briggs Type Indicator (MBTI) has little scientific validity. I went on a research journey that left me with even more questions. Why are we still taking and believing faulty tests? How come the faulty tests make more money than other tests that have proven their validity? And why are we using these tests in company-hiring processes where even the valid ones are at best not useful and at worst discriminatory?

THE CULT OF PERSONALITY

To say that personality tests are popular is a massive understatement. They are a $2B-a-year industry. 2.5 million people take the MBTI every year, and 89 of the Fortune 100 companies give some sort of personality test to potential hires and/or current employees. I am not here to say that personality tests are useless (they are not), but I am saying two things I hope you’ll at least consider. One, they are not all of equal merit; two, there are certain things they are being used for that are likely causing more harm than good.

Personality tests have been around for a long time. The DiSC assessment originated in the 1920s. Created specifically for the workplace, it divides people into one of four personality types. The MBTI came out of the work one woman did with her daughter in the 1940s (neither of whom had any psychological training). The Enneagram personality types came to South American occultist Oscar Ichazo in the 1970s when, according to Ichazo, he was visited by an archangel while in a Mescaline-induced trance.

Not all personality tests are created equally. Many originated long before we know what we now do about the brain and human psychology. The Myers-Briggs, which is the most popular, has been shown to have low test/retest reliability, meaning that when people retake the test, they are likely to get a different type than on their previous test. As Barrett points out in her book, the MBTI also tests what people believe about themselves, which research shows often has little to do with how they actually behave.

Employers who use these tests are operating in somewhat of a legal gray area. Under the American with Disabilities Act (ADA), companies cannot ask potential hires disability-related questions or ask them to undergo a medical exam. But what if personality tests include questions that prompt disclosure of psychological, cognitive, or emotional conditions? Some companies that use personality tests have been hit with ADA-based lawsuits.

Legality aside, as much as we as humans love to categorize and make everything neat and tidy, that’s not how personality works. Tests like the MBTI lead people to believe that they are either introverted or extroverted; they are sensing or intuitive. But the truth is that most people are not at the extremes of these spectra, but rather somewhere in the middle.

CAN WE TRUST ANY PERSONALITY TESTS?

The personality test that has survived scrutiny better than most others is based on what are called the Big Five personality traits. “Big Five” was coined by psychologist Richard Goldberg, who also developed the International Personality Item Pool (IPIP), an index of descriptive statements relating to each trait and on which the test questions are based.

Individuals who take the test are measured on five scales—openness, conscientiousness, extraversion, agreeableness, and neuroticism. (It would sound nicer to call the neuroticism scale “emotional stability,” but then you don’t get the easy-to-remember OCEAN acronym.)

Many of the issues found in other personality tests are absent from the Big Five. Test/retest reliability, for example, is high. People may slowly change on scales throughout their lives, but it’s much more stable overall than other tests. The Big Five also bears out the fact that most of us are not at one extreme or the other, but somewhere in the middle.

Research teams from the University of Michigan, the University of Oregon, and the National Institutes of Health developed the Big Five in the opposite manner of its counterparts. For tests like the MBTI and DiSC, important personality characteristics were determined first. Only then were questions developed. The questions that helped sort people into the pre-determined characteristics were adopted for those tests. 

The Big Five was developed using questions first. Basically, people were asked a bunch of questions, and then a statistical method called factor analysis was applied to their answers. This method essentially asks how much ones answer to one question could predict their answers to other questions. From that analysis, five overall characteristics emerged.

Finally, a scientifically sound personality test. Now we have something to use for the hiring process, right?

WHAT PERSONALITY TESTS ARE AND ARE NOT GOOD FOR

Art Markman is a cognitive scientist and professor at the University of Texas at Austin. He’s also the founding director of the Program in the Human Dimensions of Organizations. He advises against using personality tests, even good ones, in the hiring process.

Markman says that personality characteristics can only predict about 20 percent of behavior. That’s because most people act different ways in different situations. Someone might be extroverted in the sense that feel comfortable speaking in front of large groups in a business setting, but at a social gathering they may not be likely to approach people they don’t know.

Haven’t you ever taken a personality test and been forced to agree or disagree with a statement like, “I work hard,” and wanted the option of, “it depends?” You work hard at your job, but when it comes to keeping your house clean, not so much.

Markman says that sharing results of personality tests at work is a great starting point to getting to know your colleagues better. You may be surprised that a colleague who is normally quiet rated so high on the extraversion scale, because you only see them in one setting. Another useful way to use personality tests at work is when creating teams. If everyone on a team is agreeable, for example, who is going to point out a problem that might offend someone?

There are companies Markman has worked with that have used personality tests in hiring and suffered. One large organization he advised used them to only hire the most conscientious people (people who finish things and follow the rules). Who wouldn’t want all conscientious employees? Yet the company found that they were left without the kind of “renegade” people who were willing to try something totally different, and it hurt them.

Markman warns that personality tests should not be seen as a destiny, nor should specific personalities be seen as good or bad. Companies tend to do best when they have groups with a good mix of personalities rather than when they hire for particular traits.

As Barrett says in her book, people want there to be a single, universal human nature, but the variation in human minds is what has “preserved the evolvability of our species.” But we as humans want clear answers, predictability, and labels. “So even when scientists do acknowledge that there are different kinds of minds,” Barrett continues, “they try to tame the variation by organizing it into categories.”

All of this makes me feel much better about my own personality trait descriptions. Would I make an amazing emotional support animal? Clearly. But I also would never let four letters hold me back from a role I wanted, and no one else should either.

No matter your personality type, Maestro has something for you. Reach out at mastery@maestrogroup.co.