Here’s what happens in your brain when you hear a joke, and why you find it funny – or not

It all stems from our brains’ ability to recognise incongruity in the world around us and then resolve it.

Photo credit: Getty

Published: August 14, 2023 at 6:00 am

Jokes and humour are often thought of as frivolous and unimportant. In a way, this is understandable: they are, by definition, not serious. If your tax accountant, or the lawyer defending you in court, couldn’t stop wisecracking, you’d be understandably alarmed.

But the common impulse to dismiss and belittle humour, to regard it as inconsequential, is a mistake: humour, jokes, and laughter, have a vital role to play in human behaviour and interaction.

Humour is a powerful part of social bonding: we’re thirty times more likely to laugh with others than when alone. Humour is heavily intertwined with human mating behaviours. Humour is our brain’s way of displaying prowess and success, the cognitive equivalent of antlers on a stag. Also, humour and laughter are genuinely beneficial for health via their stress relieving properties.

But, what’s happening in our brains? Why do we respond, in such powerful and rewarding ways, to things that are objectively nonsensical, or meaningless?

Scientists have spent many years studying this. Which is to their credit. After all, to study how humour works in the human brain, scientists would ideally be able to induce humour in their subjects, reliably and consistently, in an experimental setting. However, ‘making people laugh on command’ isn’t an ability normally associated with professional scientists.

Thankfully, this hasn’t stopped them. A substantial amount of data has been generated regarding how humour works in the brain, and on the various types of recognisable jokes that induce it.

While jokes can manifest in a very wide range of ways (semantic jokes, linguistic jokes, static and dynamic visual jokes etc.), unsurprisingly, the most basic recognised joke is the beloved pun.

Verbal puns, the most familiar type, are where specific linguistic elements convey different meanings, simultaneously. For example, ‘Why did the golfer wear two pairs of trousers? In case he got a hole in one.’ Here ‘hole in one’ has two possible interpretations. Both are equally valid. Simultaneously.

Interestingly, puns are often the go-to jokes scientists use when studying humour. We may not actually laugh at them, but their simplicity and familiarity mean most subjects recognise the humour in puns, however feeble it may be. So, the brain’s humour processes are still engaged.  

But where does humour arise from in the brain? According to the data, everywhere. This is because jokes, and other humorous stimuli, typically include a great many sensory elements, as well as language, memory, emotion, analysis, extrapolation, and so on. These are all processed by disparate neurological regions and networks.

However, considerable data-crunching points towards a part of the brain where everything to do with jokes ‘converges’, forming a specific system for recognising humour. This system is composed of regions occupying the junctions between temporal, occipital and parietal lobes, the brain equivalent of an airport connecting three continents.

This system seemingly detects, and resolves, incongruity. Our brains know how things, like language and behaviours, should work or proceed. But, in the real world, many things don’t conform to expectations/assumptions. It seems our brains have evolved a system to recognise when this happens.

If normality is subverted, it means we don’t know how what’s going to happen, which creates cognitive tension. However, the system that recognises incongruity seemingly also resolves it, by providing an explanation, or at least a confirmation that the incongruity has no negative consequences. This removes the uncertainty, dispersing the tension.

Our brain approves of this. It means potential danger has been removed, we’ve learned something new, we’ve expanded our mental model, and more. So, we experience a rewarding feeling.

Basically, thanks to these complex systems in our brains, humour can be derived from things being surprising, unexpected or wrong in some form, as long at it’s resolved, without negative consequences.

However, if the incongruity is not resolved, humour is absent. If the answer to ‘Why did the golfer wear two pairs of trousers?’ is ‘in case the metal owl that lived in his gold bag attacked him’, that’s… not funny? There’s more incongruity, which goes unresolved. This would explain why surreal humour is often so hard to get right.

This explains much of familiar humour.

Puns? The same words having dual meanings violates our understanding of language, causing incongruity. But there are no harmful outcomes, and our brains not being relentless logic machines means we can accept two interpretations at the same time.

Slapstick? People don’t usually injure themselves in exaggerated ways, so that’s incongruous. But they’re ok, just embarrassed? Incongruity resolved, all’s well, so humour occurs.

This is also why, unlike music, jokes struggle to have the same impact when repeated. The resolving of incongruity is a key part of humour. If it’s familiar, the incongruity has already been resolved.

Humour is a uniquely human phenomenon with many other complex variables that affect it. Status, emotion, motivation, social cognition, memory, arousal, and more. But, according to the latest science, the detection and resolution of incongruity is its neurological bedrock.

Humour is essentially our brain going “This isn’t how things usually work… but I’m okay with it!”

It may sound frivolous, but the neuroscience of humour is no laughing (grey) matter.