The hidden psychology of ‘know-it-alls’: Why they think they know everything

The hidden psychology of ‘know-it-alls’: Why they think they know everything

You don't want to do it like that, you want to do it like this...

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Published: November 3, 2024 at 8:00 am

We all know someone like it. You probably work with or are even related to one. And with Christmas approaching, the season of office parties and family gatherings, you’re increasingly likely to have to interact with one and rediscover just how annoying they are.

We’re talking about the ‘know-it-all’. Individuals who will enthusiastically lecture you about any topic or area, despite blatantly having little to no expertise in what they’re talking about. And often, even though you do.



Why would anyone assume superior knowledge to everyone else, about every possible subject matter? There are several quirks of human psychology that help explain this behaviour.

One is the phenomenon of ‘naïve realism’, which describes how people instinctively assume that their perception of the world reflects objective reality. In actuality, everything we perceive and ‘know’ about the world has been filtered through a complex mesh of cognitive biases, sensory shortcuts, shifting emotion-infused memories, and more.

What we believe is reality in our heads is often markedly different to what is reality, but we don’t recognise this happening.

As a result, we regularly encounter people whose understanding of the world is very different to our own. But naïve realism means we assume that those who understand the world differently are wrong.

For a seemingly large number of people, this results in an irresistible urge to ‘correct’ others. It may be 100 per cent well intended, but that doesn’t make it any less grating.

However, this can’t be the full story. Countless people believe others are wrong, yet never do or say anything about it. And the typical know-it-all seldom waits for you to be ‘incorrect’ before lecturing you.

Another potential cognitive bias at work, proposed in a recent study by Gehlbach, Robinson, and Fletcher, is ‘The illusion of information adequacy’. Put simply, this describes how though many people lack sufficient information to make correct judgements about something, they'll assume the opposite. It’s logically very hard to recognise and take account of what we don’t know.

For example, someone could notice that their female co-worker keeps running to the bathroom to be sick every morning. Based on just this information, they could conclude “she’s pregnant!” and decide to congratulate her.

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At this point, she could reveal her sickness is the result of chemotherapy. As the first person made a conclusion based on painfully insufficient evidence, they had the illusion of information adequacy.

A combination of illusion of information adequacy and naïve realism, respectively, can lead to people believing that they know more than they do. In their minds, their knowledge is superior to others and they must help correct it.

But even then, there’s still clearly more at work. We all potentially deal with these cognitive biases, but by no means everyone is a know-it-all. It seems that some people have a certain extra quality that means they have no issue with shoving their conclusions into other people’s faces.

It may be a status thing. Some people are more sensitive to social status, and constantly pushing their ‘correct’ opinions onto others may be a reliable way of asserting (subjective) superiority, and dominance.

The human brain also typically craves a sense of autonomy – wanting to have control over one’s environment. Some may crave it more than others, and what could be more effective as a sense of control than dictating what others think?

Then there’s our old friend, the Dunning-Kruger effect: the cognitive bias where people with limited competence in a certain area tend to overestimate their abilities. Their lack of intellectual insight means they struggle to recognise when someone else knows more than them, meaning they’ll confidently argue with those who are better informed.

And because people often respond more to confidence than accuracy, they often get away with it.

If this happens often enough, across enough subjects, you could convince yourself that you’re an expert on pretty much everything, even though the opposite is true.

It could be that to become a know-it-all, you have to know far too little.

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