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Are personality profiling tools worth it?


I posted something that was a little critical of the Myers-Briggs Type Indicator (MBTI) and, oh. my. goodness!  

It was an excerpt from Lisa Feldman Barrett’s excellent book, “71/2 lessons about the brain” which suggested that…

“You can’t measure behaviour by asking people about their behaviour”.

And “Why do the test results seem so true when you receive them? Because the test asks what you believe about yourself.”

The reaction, particularly on LinkedIn, was pronounced. 74,000 views and counting.

So many people had an opinion on it and other personality tests. Some rushed to the defence of MBTI (and personality assessments more generally), others delighted in its being likened to a horoscope.

Of course, even calling them “tests”, is a point of contention. The MBTI is an “indicator”, for example, not a test.  

But let’s not get sidetracked by semantics right now. 

Instead I want to talk about these…let’s call them tools…and, more specifically, and because it’s my patch, where they can help you influence behaviour.

So I’m not going to be talking about their use in recruitment, or job performance or team dynamics, and I’m not going to go into the details of any instrument in particular.

Instead I want to focus on how personality profiling tools in general can help you understand and influence your own behaviour, or someone else’s.

Major benefits of personality profiles

As I see it, personality profiling tools have two major benefits when it comes to behavioural influence: Self-awareness and empathy.

In terms of self-awareness, these tools play back to you what you believe about yourself. As Feldman Barrett writes, “The results summarise (your) beliefs and give them back to you, and wow, they fit so well!”

As far as I’m concerned, if it focuses your attention on your strengths and weaknesses, even momentarily, that can be a good thing. My beliefs about myself are important information - for myself and for others.

When displayed in a report with a nicely boxed categorisation - you’re an ITJP or “Steady” type, or high in Agreeableness, for example - it can make the scramble in your head feel more controllable and comprehendible.

As humans we are drawn to sifting and sorting. To in-grouping and, by extension, out-grouping. Categorisation helps us navigate the complexities of life. It helps us know where and how we fit.  There is a big downside to this, of course, because our tendency to stereotype and discriminate between people can be extremely harmful and hurtful. All the more reason for us to be aware of this innate drive to categorise.

Aside from self-awareness, personality profiling tools can also stimulate our curiosity about how others may be classified. And this is the other significant upside - it can increase interest and empathy. Why might I be challenged by that person? It’s not because they’re an idiot, it’s because they see the world differently.

And let’s not underestimate the power of this.

Personality profiling tools are a multi-billion dollar industry. Why? Because to succeed, we need to work with and through others, and so getting to know what makes people tick is valuable information. 

And let’s not forget, we are all heroes of our own story, and love to hear about ourselves. From hearing our name mentioned across a noisy room to reading a report effectively telling us what we already think we know about ourselves, we are fascinated!  

But therein lies the major concern. These tools can (perhaps inadvertently) lull us into thinking we have the definitive user's-guide-to-self, or give us false confidence that we know how others tick, when they are based on a shaky premise.

The shaky premise? That what we think is what we do.

Potential shortcomings of personality profiling tools

This is where things get touchy when it comes to personality profiling tools. Validity. How valid (or accurate) are these tests?

Without being a lifelong student or practitioner of any of the tests, I am not going to do justice to the rigour of each. Yes, I covered the main ones in my psychology degree, but that gave me a general awareness, not knowledge about how the sausage is made.

For further probing, I’ve included some resources at the end of this piece.

But what caught my eye and why I posted Lisa Feldman Barrett’s perspective was this. 

The test results seem so true ”because the test asks what you believe about yourself.”

These tools are like looking in the mirror.

But what do we know about mirrors? They are not how other people see you. Your image is flipped. That’s why people prefer photos or themselves that are reversed - we’re familiar with our reversed (mirror) image. Our friends prefer the photos of us that are not reversed because that’s why they are used to.

So yes, these tests can feel accurate but they are usually limited to your beliefs about yourself. Do those beliefs marry up with how you act? How people observe you acting?

Feldman-Barrett again: “You can’t measure behaviour by asking people about their behaviour. You have to observe that behaviour in multiple contexts.”

The point I took from this is beliefs don’t always translate to actions. 

I’m reminded of a health study from a number of years ago (McKinsey Retail Healthcare Consumer Survey, 2012) that asked people to rate their health-status and then compared the self-rating with a derived health profile (i.e. observable health metrics like blood pressure).

The upshot? 67% of people with a chronic health condition believed themselves to be in “good or excellent health”.

Or what about the 60% of Americans who claimed they’ll turn out to vote but only 40% did?

Or my fellow Victorians, 50% of whom said they eat healthily, but only 7% ate vegetables on a regular basis.

Again, self-reported answers tell us something. They tell us what people believe about themselves. But that doesn’t, and can’t, make it predictive.

And here’s where some advocates of personality profiling tools pop up and say, they’re not designed to be predictive!

They’re being used for a purpose never intended.

That may be true.

But I am certain businesses are not spending $2 billion to not get a sense of how their staff are likely to perform. And many businesses selling such tools are doing so on the promise of predicting job fit or performance.

And let’s be frank. Bolstering self-awareness and empathy are only helpful if they help make things better on an ongoing basis.

So when it comes to personality profiling tools to help you influence behaviour, what to look for and how to use them?

What to look for

Again, I haven’t done a PhD comparing personality tests, and have no stake in any of the camps, so you’ll need to do your own research.

Two things that you may wish to focus on, though, are the tool’s reliability and validity.

In terms of reliability, if you retake the test, you should get the same result. The DISC profile and Five Factor Model (aka Big 5) seem to do well on this.

And validity. The tool should measure what it is supposed to measure. Again, the Five Factor Model does well here. It says it measures five stable personality traits and it does. It doesn’t, for example, accidentally measure transitory emotions.

How to use personality profiles to influence behaviour

When it comes to using personality tools to help influence action, I need to be very clear that no test that I’ve seen is designed for this purpose.


Being aware of how you see yourself can be useful when contemplating how to approach a situation or relationship. And being curious about how someone else might view the world is also core to influence.

If I am highly contentious, I might find myself in conflict with someone who isn’t and so need to devise ways of managing that.  A buyer who is less open to experience, may need more assurances than others. A Dominant type is unlikely to respond to a long winded, detailed email from me, and so on.

Which brings me to why I use a DISC-esque version in my training.

First, frankly, because it is widely known. Because it is familiar. That’s a trap, I understand, because just because something is popular doesn’t mean it is best. But I am not looking to educate my clients on the tool itself, I am looking to give them an easy way to analyse opportunities to influence.

Which is the second major reason I use DISC rather than the Big 5. I was looking for something that makes it easy to use in the moment. When speaking to or meeting with someone for the first time, how can they quickly appraise them, form a hypothesis and adapt their approach accordingly?  What behaviours should they be looking for?

So is there merit in using personality profiles? I’d argue, yes. 

Do they tell you anything new about yourself? Possibly not. But it takes what’s in your head and puts it on paper, and that can be powerful. Even if you get a result you think is rubbish, that still tells you something about who you think you are not, and by extension, who you are.

Are they subject to manipulation and gaming? Totally, particularly the short-form, free quizzes. You have to pay top shelf for rigour.

Can anyone be accurately placed in a box? And should they be? No. Rationally, no. 

But in our struggles to understand ourselves and others, personality profiling tools at least start contemplation, if not conversation.

Anything that helps us tune into ourselves and others is, from my point of view, a worthwhile exercise.

I’ll leave it to well versed others to argue the relative merits of the different personality profiling tools.

Because from what I’ve observed, there seem to be two types of people in this world. Those who believe in…Ah, you get the idea!


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