Oftentimes, after I just meet someone and I tell them what a person trained in Industrial-Organizational (I-O) psychology does, the well-meaning person asks me what I think about the Myers-Briggs Type Indicator (MBTI). I often smile and try to say, as respectfully as possible, that I like some other assessments better. What I don’t do is tell them why.
Any assessment, be it to measure employee engagement, job performance, or personality type, must contain two crucial elements: reliability and validity. Briefly, reliability is consistency of measurement. If you get on a scale and it says you weigh 135, and then you get on it three minutes later and it says you weigh 170, it’s probably not a very good scale. The same thing applies to assessments. If you take an assessment on Tuesday and it says you are an introvert, and then you take that same assessment the following Friday and it says you are an extravert, it probably isn’t a good assessment.
Setting that aside for a moment, most versions of the MBTI use a “forced-choice” methodology in which the respondent is asked to choose between two often competing alternatives, such as, “Would you rather MBTI EXAMPLE 1” or “Would you rather MBTI EXAMPLE 2”. But what if you sort of like (or hate) both? In this instance, you can only choose one response. Hence, you are literally forced to choose a response. This is important because, all things being equal, a forced-choice format will reduce the reliability of an assessment. For the MBTI, that means that the methodology it uses will likely result in a lower degree of reliability, or the consistency, of the results it yields.
But as important as reliability is, it is not the most important component when using an assessment. That honor goes to validity. Put simply, validity is how well an assessment measures what it claims to measure. And, what many often overlook, validity is situationally-specific. For instance, the NFL uses an assessment called the Wonderlic to assess cognitive ability. Hundreds of studies have shown that the Wonderlic is great at measuring cognitive ability. So, the Wonderlic must be valid, right? Not necessarily. Not only must an assessment measure what it claims to measure, but the validity of an assessment also depends on how the information it provides is used. In the NFL’s case, they have found that higher Wonderlic scores are often associated with better performance from quarterbacks. If you are a football fan (and maybe even if you aren’t), you can probably recognize that quarterbacks must be pretty smart to figure out all those crazy defensive schemes. In this case, using the Wonderlic to help select quarterbacks makes it valid in that situation, because its use is appropriate. Conversely, if the Wonderlic was used to determine who would be the fastest bicyclist in a group of people, it probably wouldn’t be very valid unless cognitive ability helps folks to peddle fast.
As you might guess by the title of this blog, the MBTI is not very valid when it is used in organizations. In fact, it may not be very valid at all. The MBTI was developed partly on the work of Carl Jung (a famous psychologist), but also partly on the originator’s own unsupported philosophy of personality. The problem with the MBTI is that there isn’t any evidence that the personality types ostensibly measured by the MBTI actually exist on the famous polar opposite continuum it claims (e.g., you are either Thinking or Feeling). Even if the MBTI were valid, though, there is absolutely no evidence that it can help make teams more productive, that it can help employees relate with and understand each other better, or that it can make an organization more productive. Without that evidence, we cannot be certain of its validity when used in organizations. And without validity, you have nothing.
So, why do so many people I meet ask me about the MBTI, and why is it used in as many as 89 of the Fortune 100 Companies? Well, it’s because, on its face, it appears to be valid. Think about it. You’ve just answered a bunch of questions that have forced you to take a stance. You said you’d rather spend a quiet evening at home rather than go to a party after an exhausting week at work. Now, the MBTI tells you that you are an “I” and not an “E”. It must be right – right? Well, no, not necessarily. If the personality types aren’t necessarily polar opposites, and if your answer has no bearing on how good an organizational team member you would be, then it isn’t valid anyway. It just feels like it is.
So, we at Marcus Management Consultants, LLC do not use the MBTI because there is no evidence that it measures what it purports to measure, that whatever it does measure probably doesn’t measure it consistently, and that it’s use is inappropriate for most (if not all) organizational applications. And because of that, you shouldn’t use the MBTI either.