The Science

What is Personality?


Personality is real and it matters.

Trying to make sense of people's behavior is fascinating. Why are some people always excited while others are more anxious? Why do some people love traveling while others are happy at home with the same old routines? How come some co-workers are constantly procrastinating and others seem to be working 24/7 feeling guilty if they take a day off? I guess if you found your way to this website you can guess my answer:


Personality, is that even a thing? Don't most people act based on the situation they are in? Yes, and no. Like any complex animal our behaviors will definitely change with the situation we are in. We might be more social and extraverted with our friends than at home with our family. That's normal. But that doesn't mean that we don't have a core tendency, a baseline that comes easiest to us. We all do. And that's what personality psychology cares about.

How do we measure Personality?

There are so many different personality models out there. From Astrology, Colors, Meyers-Briggs (16 Personalities), DISC, Enneagram, to the Big 5. Are all of these tests true and just have different perspectives on personality?



Most of these personality tests are not used by psychologists and for good reason. They don't work. If you take the weak tests twice, with a month in between, for many you will get a different result the second time (in science speak: they have poor test-retest reliability).

Your instrument of measuring personality doesn't work. It's Like having a ruler that stretches and grows from day to day. You wouldn't use it to build things because you couldn't trust it. Which one of these tests is reliable and actually predicts behaviors and things in life (like success in a job or happiness in a relationship)?

The Big 5

The Big 5, or OCEAN model has unified modern personality psychology. It is the gold-standard. But why always 5 traits? What's up with that? Imagine asking a bunch of different people a lot of questions related to behavior, emotions, and personality. All of them randomly chosen out of a large set of questions.

You have no theory or idea what personality looks like. So you just collect the answers from these questions. If people would answer these questions at random and one answer doesn't seem to be connected to any other answer then we couldn't really make a model. Each answer would only stand by itself, unconnected to all the others. Kinda like this:

personality questions

But that is not what we have found over the last 30 years. Time and time again, when you look at the answers of people you find that some questions clump and cluster together. Questions about social activity, seem to clump with risk taking, and positive emotions.

Questions about cleanliness and order seem to predict answers on questions about work-ethic and following of rules. Through a fancy statistical method (exploratory factor analysis) the results always seem to show 5 big groups or factors:

personality questions clustered

The Big 5 are born. Let's quickly introduce our 5 main personality traits.

big 5 personality traits

Openness: is about curiosity, openness to new experiences, aesthetics, appreciation of abstract ideas (basically Creativity & Curiosity).

Conscientiousness: is about organization, rules, planning, getting things done, cleanliness, and hard-work.

Extraversion: is about your social energy, but also about risk taking, and overall positive emotions (happiness).

Agreeableness: is about your consideration for other people, empathy, compassion.

Neuroticism: is about negative emotions like anxiety, sadness, fear, pain as well as frustration emotional volatility and anger.

When you take a Big 5 personality test you will get your results for each of these 5 trait dimensions. Which represents your basic personality profile. Imagine everyone of the Big 5 like a dimensions going from low to high. For Extraversion it would look like this (with my average Extraversion score as a dot):

extraversion spectrum

So people at the high end of Extraversion are very social, outgoing, energetic, sometimes risk taking and generally happy. People on the low endpoint are more shy, aloof, introverted and lower in their social energy and risk taking.

The problem is people are not a dot on this spectrum. One single number is not able to adequately represent your daily behavior on any of the 5 dimensions. On any given day, we all exhibit a wide range of behaviors that are both more introverted and more extraverted. So we are all somewhat flexible in how we act depending on the situation.

A better way of visualizing your result for one personality trait is with a distribution centered around your average score.

extraversion distribution

Your personality profile is only a low-resolution (broad-strokes) approximation of you as a person. You are more nuanced and complex than 5 averages on 5 trait dimensions. You have fears, dreams, hopes, goals, values, interests, and a story about your life and identity. So while personality doesn't capture everything about a person it is the best thing we can get with a 10 minute test.

Especially if we combine your unique personality profile with your values and interests we can get a pretty decent picture of a person. We can get an idea how that person interacts with other people (Extraversion + Agreeableness).

How hard working and organized they are (Conscientiousness). How excited they are about ideas, art, and learning new things (Openness to experience). And also how they react to negative emotions, and how likely they are to be anxious, sad or frustrated and angry (Neuroticism).

Why Myers-Briggs is nonsense

The Myer's Briggs Type Indicator (MBTI) has a few fundamental problems. The central issue is that each of its 4 arbitrary personality dimensions is destroyed when it is cut in half at the 50%. For Extraversion this means that everyone above 50% is classified as Extraverted (E) and everyone below as Introverted (I).

The problem is the arbitrary nature of this cut. Someone who scores 53% (Person A in the image) will be an E type, while Person B who scored 48% will be classified as I. A third test-taker (Person C) scores at the extreme end of Introversion and also scores I. Person A & B are basically identical in their distribution while being in completely separate personality type buckets, while Person C who is the most different gets the same personality type as Person B.

Meyer's Briggs is nix

Can I change my personality?

If personality is a stable part of who I am - can I change it? That is the question isn't it? The short answer is yes, but its not easy. Sometimes I come across people who act as if we can just change who we are at a drop of a hat without a problem.

Are you depressed? Stop being sad! Are you nervous when speaking in public? Just calm down and show confidence! As if your core personality is a helium balloon that you can just fling around whenever you feel like and with that changing your perceptions, emotions, feelings, and behaviors.

Personality is a balloon

Anyone who has ever dealt with mental health problems knows how patronizingly ridiculous that approach to human nature is. No, we can't just change our core personality without putting any effort in (especially once you're 20+).

Personality is a rock

That doesn't mean you can't change your personality. It just means it won't be easy and it ain't gonna happen in a week. Change takes time and it's hard. Your way of interacting and seeing the world is not like a balloon that you can change whenever you feel like it.

It's more like a large rock or boulder you're slowly trying to push ... uphill. The beginning will be hard and it feels like the rock is not moving at all. Even after having made some progress uphill if you don't continue pushing over the first hillock the rock will slide down again to your baseline valley.

I'm not saying you can't change your personality. You definitely can. Just be realistic about it. It will take effort and time. And even then a hyper introvert with social phobia will probably never become the super comfortable public speaker full of energy. But you can definitely stretch than part of each trait dimension to be more flexible in how you respond to the world.

For a strong introvert this means being able to enjoy intense social events when they feel like it or need to without becoming stressed out. For someone with very low Conscientiousness it might mean being more organized and hard-working when it matters.

Can I change my personality?

We should all aim to stretch our personality tendencies along the axis of each trait. This will make us more stable and flexible when life throws its difficult times at us. So go and improve your strengths and work on your personality pitfalls and blind spots.

Why does Personality matter for my career?

Picking or changing careers is hard. There is a lot of uncertainty. Will I enjoy working there? Is the company a decent place to work? How will my boss treat me? Are the co-workers fun? Is my daily role actually something I want to spend my days doing?

Am I contributing to something bigger than myself? The list goes on. One of the fundamental insights into most of these questions is who you are. You as a person, at your core level.

Your unique personality profile, your strengths and weaknesses. The way you act around other people, how you deal with stress, how organized you are, how enthusiastic you are about abstract ideas - all of this should inform your thinking about your career. It won't tell you about your new boss or your co-workers but it will give you much needed clarity in realizing what you are actually good at.

It can also help you understand what things in life provide meaning and value to you. Is it helping other people? Is it solving complex problems? Is it creating things? Perhaps it simple is stability and the safety of a stable job with people you like. Whatever it is - you should figure this out before changing careers or jumping into your first job.

If you haven't taken the personality-career test - give it a try: