“Go ahead and try me on, there’s nothing left to fear, I’ll find right where you belong, by looking between your ears.” The Sorting Hat – Harry Potter: Magic Awakened 

If only we humans had the same ability as the famous Hogwarts Sorting Hat. Imagine being able to use the fictitious power of legilimency, which, in the words of J.K. Rowling, “enables [the Sorting Hat] to look into the wearer’s head and divine his or her capabilities or mood,” and by doing so puts the future wizards in the proper wizarding house.1 It is possible that we do have Sorting Hat abilities of our own, absent the magic. 

Visit the website of Psychology Today and you can participate in dozens of personality tests designed to assess certain aspects of personality. In an average of 25 minutes per test you can find out about your Bipolar Depression Scale, Love Diagnostics, Coping Style, Procrastination, Flirting Personality, Driving Personality, Burnout, Success Likelihood among other important and/or curious traits.2 (I’ll admit, I really don’t want to find out about my Driving Personality). Another possibility is to go to SimplyPsychology.org where you can find out where you are on the scales of the Five Big Personality Traits signified by the acronym CANOE: Conscientiousness, Agreeableness, Neuroticism, Openness to Experience, Extroversion.3 While these Big Five are commonly used by psychologists and behavioral experts, this self-administered instrument is mainly for the curious. These two examples are just a few of the dozens of psychometric options available.   

The surveys discussed above are primarily for the curious, casual observer who finds the results insightful about their own traits and tendencies. However, there is also a significant interest in the corporate world for sorting personalities; approximately 80 % of Fortune 500 companies use personality instruments, typically for hiring decisions, performance evaluations, or teambuilding.4 In fact, personality testing for employers was a $2 Billion per year industry in 2019 and is expected to reach $6.5 Billion by 2027.5 The test most used by corporations is the Myers-Briggs Type Indicator (MBTI) which evaluates a person’s responses to survey questions to determine where they fall on a spectrum of four sets of opposing types: extraversion vs. introversion; intuition vs. sensing; thinking vs. feeling; and judging vs. perceiving. The results place the subject in one of 16 Personality Types to be then used by the employer in several ways.  

Ever since the idea of introversion versus extroversion was expanded by Carl Jung in 1921, those two binary definitions have dominated the general discussion of personality.6 Some modern researchers have moved away from Jung’s view of introversion and extroversion as too simplistic, but there are still many who agree with his principles. Susan Cain’s book Quiet focuses primarily on the power of the introvert and includes many examples and discussions of the different theories. To confuse the issue even more, Cain recognizes, “There are almost as many definitions of introvert and extrovert as there are personality psychologists.”7  Cain’s primary foundational thesis in her well-researched book is that extroversion has become our cultural ideal, much to the chagrin of introverts such as herself. By implication, introverts are sometimes believed to not have the leadership markers desired by most organizations for executive level roles. Cain’s arguments are convincing and join the growing concern that many experts have regarding the proper use of personality tests in workplace settings.  

According to Randy Stein, a psychologist at California Polytechnic State University, the objections to using personality tests in business fall into a few primary topics. One issue is that personality tests tend to assume that personality is static while research shows that personality is fluid and can change due to stimuli or effort. Most assessments make the claim that their tests will reveal a person’s “true” self that is somehow disconnected from their own sense of self. This assumes that there is a code to crack to get beyond a person’s supposed facade that may be projected in normal interactions. Also, assessments tend to assume a causal effect of personality to a person’s behaviors. Stein states that “the causal path from trait to behavior cannot be assumed.”8 Learned behaviors, such as strategies to deal with conflict aversion, can help people to act in a different way than their personality type. Stein also identified a claim of MBTI-type instruments, assuming that one’s personality type is inborn and immutable. Stein states that this claim is not proven in scientific research. 

Perhaps the most significant issue regarding using personality tests in business is the legal risk that may be associated with them if they are not properly interpreted or used in absence of other tools. Companies such as Best Buy, CVS and Target have been found liable for discrimination due to their use of personality tests in hiring and in some cases paid millions to settle the claims.9  

In addition to the concerns about accuracy, validity and ethical issues surrounding the use of personality tests in business, there is also a philosophical question: should personhood be replaced by personality type? I know from personal experience that we businesspeople love metrics. We measure a vast array of statistics from revenue per unit, cost of goods sold, customer acquisition costs, social media impressions, return on investment, etc. I always loved those types of metrics and learned a lot from them about my business. But, when it comes to people, is it valid to reduce a person’s predictable potential down to “a calculation on a giant psychometric slide scale?” (Yates)  

Has our current desire to categorize people according to certain personality traits (whether inborn or learned) proven to be productive in society or business? Not really. 

Harvard Business Review looked at this question related to the predictive success of various tools for hiring. The article mostly relied on work done by Frank Schmidt who reviewed a century’s worth of data. The findings showed that among the seven types of hiring tools used, personality tests were the second worst method of predicting future job performance (only job experience was worse). In fact, the use of personality tests was 1/3 as effective as either the use of multi-measure tests (cognitive ability + personality + interests) or cognitive tests alone.10 

Despite this research to the contrary, the use of personality tests is becoming a tidal wave that the corporate world is not likely to reverse. Using the MBTI assessment jargon, are you an INTJ or an ESFP or an ISTP? The answer to that question may decide your future career prospects.  

In my own career, I have experienced the use of MBTI or similar instruments as an informational exercise in corporate conferences. I have also personally taken and as a hiring manager used various predictive behavior instruments in the interview process. I generally paid great attention to the results as a window into my own and a potential candidate’s strengths and weaknesses. I never used these instruments as a means to making a hiring decision but as a tool to target questions and topics to focus on during an interview.

In the HBR article, the advice to hiring managers is to decide if the instrument they use is predictive of future performance. The conclusion is that they probably are not due to “limited validity, low re-test reliability, lack of norming and an internal consistency (lie detector) measure.”11 With all of these potential trip wires present, the best methods to use in making the hiring decision are the three with the highest correlation to later performance: 1) Multi-measure tests (cognitive ability + personality + interests, 2) Cognitive ability tests alone, and 3) Integrity tests. In any case, these instruments should be treated as tools in the hiring process, not the deciding factor.  

In the Harry Potter books, the Sorting Hat was magically able to divine whether a wizard in training was brave, ambitious, loyal or wise or something on the opposite end of the scale. We mere humans must rely on other means which are much less foolproof. Let’s hope that the resulting algorithms of these tools are put in the proper perspective.  

Notes 

1 Wizarding World: The official home of Harry Potter. (n.d.). Retrieved April 22, 2024, from http://wizardingworld.com 

2 Psychology today: Health, help, happiness + find a therapist. (n.d.). Psychology Today. Retrieved April 22, 2024, from http://psychologytoday.com 

3 Simply psychology. (2023, February 19). Simply Psychology. http://simplypsychology.org 

4 Leikvoll, V. (2022). 80 % of Fortune 500 Companies Use Personality Tests, But Are They Ethical? Leaders, 50–55. 

5 Goldberg, E. (2023). The $2 Billion Question of Who You Are at Work. New York Times. 

6 Yates, C. (2024). Sorting the Self: Assessments and the Cult of Personality. Hedgehog Review, 26(1), 32–44. 

7 Cain, S. (2013). Quiet: The power of introverts in a world that can’t stop talking. Crown. 

8 Stein, R., & Swan, A. B. (2019). Evaluating the validity of Myers‐Briggs Type Indicator theory: A teaching tool and window into intuitive psychology. Social and Personality Psychology Compass, 13(3). https://doi.org/10.1111/spc3.12441 

9 Ibid, Leikvoll. 

10 Martin, W. (2014). The Problem with Using Personality Tests for Hiring. Harvard Business Review, 50–52.