The Problem with Personality Testing

Why Most Personality Tests Don’t Really Know You – Here’s What Science Has to Say

Have you ever taken a personality test that presented you with your "true self"? Maybe it labeled you a “Mediator,” a “Commander,” or an “Advocate.” These titles can feel so validating, right? They tell us we’re unique in some oddly precise way, like, “Oh! That explains why I organize my sock drawer by color!”

But here’s the kicker: a lot of these popular personality tests are not scientifically sound. I’m talking about those personality tests that have taken over the internet (not to mention HR departments), from the Myers-Briggs Type Indicator (MBTI) to the Enneagram. As a psychologist, I get the appeal, but I’m also here to tell you that they often just don't cut it in the science department. Let’s unpack why.

The Problem with Personality "Types"

First off, a lot of these tests rely on a type-based model. MBTI, for example, says you’re one of 16 types – maybe an INTJ or an ESFP. Types, however, are super limiting. Research has shown that human personalities don’t really fit into neat little boxes; instead, they exist along a spectrum. Imagine telling every runner they’re either a sprinter or a long-distance runner with nothing in between. Crazy, right? Most people are somewhere in the middle. That’s exactly how it is with personality – more a sliding scale than a "You’re in, you’re out" system.

Scientific psychology often prefers what we call the “Big Five” model. It measures personality across five major dimensions – openness, conscientiousness, extraversion, agreeableness, and neuroticism (yep, that last one sounds dramatic, but it just means emotional sensitivity). Each trait is a continuum. So you’re not "an introvert" or "an extrovert" per se – you’re somewhere on a scale between the two.

Are You the Same Person All the Time?

Another issue with these tests is something psychologists call situational variability. Think of it this way: Are you exactly the same at work as you are when you’re with your best friend? Or with your family? Probably not, right? You adapt and show different sides of yourself based on where you are, who you’re with, and what you’re doing.

Most commercial personality tests don’t account for this. They assume you’re one static “type” all the time, which oversimplifies things and just isn’t how we work as humans. True scientific approaches to personality take into account that we have various roles and contexts, which all bring out different traits.

Validity and Reliability: The Science Behind a Good Personality Test

Okay, here’s where things get really juicy. In psychology, if we’re going to call a test “valid,” it has to actually measure what it says it’s measuring. If a test tells you it’s measuring your “true self” or your potential career path, there’s supposed to be evidence to back that up – and most commercial personality tests just don’t have it. For example, MBTI has been studied for years, and it shows low reliability (meaning you might get a different result every time you take it) and low validity for predicting real-life outcomes like career success.

True psychological assessments go through a lot of rigorous testing to ensure they’re reliable and valid. That means they’ve been given to large, diverse groups of people, and the results are consistent over time. If a test doesn’t meet these criteria, it’s not much better than flipping a coin.

The Illusion of “Insight”

I get it – personality tests feel good because they give us a sense of clarity. It’s fun to have labels and easy answers for our quirks and habits. But just because something feels insightful doesn’t mean it actually tells us much. Often, personality test results are so vaguely flattering they feel like horoscopes: “You’re driven yet compassionate!” (Who wouldn’t love to hear that?)

Plus, it’s easy to fall into something called the Barnum Effect, which is when people believe broad, generalized statements apply specifically to them. Think about it: if a test tells you, “You work well with others but need time alone to recharge,” well… that applies to most people!

So… Should We Never Take These Tests?

Not necessarily! Popular personality tests can be fun conversation starters and offer a jumping-off point for self-reflection. Just don’t take them as hard facts about who you are.

BOTTOM LINE

So… Should We Never Take These Tests? Not necessarily! Popular personality tests can be fun conversation starters and offer a jumping-off point for self-reflection. Just don’t take them as hard facts about who you are.

If you’re interested in a deeper, more accurate understanding of your personality, I’d recommend something based on the Big Five model. In fact, I developed a personality test called "Personality Compass" that is based on the Big Five. This tool includes modern questions, relevant to your life experience (so it's fun to take), along with a score report that dives into the strengths and drawback of your traits as they currently are.

Take the Personality Compass Assessment Here! (It's free, by the way)

And remember - personality changes and we are in the driver's seat when it comes to the traits we develop. So, considering your test results as a starting point!