There are some things that seem to be almost beyond the reaches of scientific explanation. While neuroscience can explain dreams, intelligence and memories; it seems strange to imagine that there might be a neural basis for humour. What could be the evolutionary benefit of having a built-in appreciation of knock-knock jokes? And how could neurons and brain structures possibly generate something as abstract and subjective as humour?
The Two Elements of Humour
You know how explaining a joke can kill it and prevent it from being funny anymore? Well, hang onto your funny bones – because we’re about to explain all of humour – so let’s just hope that doesn’t ruin jokes in general for you.
One thing you perhaps won’t have considered in the past, is that humour is actually made up of two parts. These are the ‘cognitive element’ and the ‘affective element’. The cognitive element refers to our ability to detect and appreciate jokes and to understand where the punch line is – generally this is thought to be the result of experience and occur in the temporal and prefrontal regions (the areas associated with higher reasoning). The affective element meanwhile, is the resulting feeling and genuine experience of humour – this is the part that psychologists and neuroscientists are particularly interested in.
There have been many studies looking at humour, but some of the most common in recent times look at the role of neural circuitry, often using fMRI scans to look at what’s happening in the brain when we find something funny. Unfortunately, these studies have failed to tell us much, other than where the cognitive element takes place. This means that we’re instead left with theories that aren’t actually supported by evidence, but represent our current ‘best guesses’.
The Computation Model of Humour
One popular theory of humour is what’s known as the ‘computational model’, put forward by I.M. Suslov (1). This theory postulates that our brains tend to stay a few steps ahead of whatever we’re hearing as a way to manage resources. When someone talks to you, you are listening, but you are also thinking about what they’re likely to say next, what their motives are and what you’re going to say in response. In short, we predict the outcome and we prepare for it.
Humour occurs then, when someone says something that we weren’t expecting. The idea is that we’re left in an incongruent state and with lots of ‘neural energy’. This energy needs to be dissipated, thus it is sent to the motor cortex causing convulsions and laughter.
There are problems with this theory however. For instance, it fails to explain slapstick humour, or why we find some jokes funny even when we ‘see them coming’. It also doesn’t really explain puns, or many other types of humour.
Incongruity theory is the currently reigning theory of humour which is similar to, but distinct from the computational model. In incongruity theory, it is suggested by Arthur Schopenhauer (though first postulated by Aristotle), that we laugh when a concept fails to explain an object or situation. Thus most jokes will involve a ‘set-up’ and then a ‘twist’ (2).
Again though, this theory of humour fails to explain why we laugh at slapstick or puns, at awkward situations or at a range of other ‘types’ of humour.
Superiority theory suggests that we laugh at others who are worse off than us (a phenomenon known as ‘schadenfreude’), because it makes us feel superior. This theory was also one suggested by Aristotle, as well as Plato.
Relief theory states that laughter is a mechanism used to reduce tension and can thus relieve fears or stress. This theory suggests that we laugh as a way to overcome inhibitions, to reveal suppressed desires and to deal with stress, confusion or excitability of other kinds. It could be seen as a way of explaining the computational model, whereby incongruence is just one ’cause’ of tension. It could also explain why we laugh when tickled which also ‘excites’ the nerves. This can also explain why we joke when nervous.
Could relief theory explain our enjoyment of puns or slapstick? Potentially, if you think that our empathy would cause a lot of psychic firing when witnessing someone fall over (‘mirror neurons’ cause us to literally ‘feel’ for other people), or that a pun might cause a moment of slight confusion as a word has a double meaning.
The flaw with many theories of humour is that they fail to take into account the broad range of things that can make us laugh. Have you ever heard a funny noise and laughed uncontrollably at the idea? Or have you perhaps imagined saying something strange to someone and laughed to yourself about it? We can laugh at our own failures and we can laugh at other people admitting something we’ve often felt. We can laugh at a bad drawing and sometimes we can laugh ironically at a joke purposefully designed to be unfunny…
While theories like incongruence theory don’t really account for all those scenarios, relief theory comes the closest to doing so. Someone admitting a guilty secret might let us laugh about something that has been causing us stress – giving us permission to ‘let go’ because we now know other people feel the same. Likewise, laughing at a funny noise can be the result of not knowing what caused the noise, or of imagining something else making the noise that doesn’t fit.
And if we take this theory to be the most all-encompassing, it could then be suggested that a sense of humour could be indicative of a person’s thought processes. If someone laughs at an admission, it tells us that they sympathize, and if someone laughs at a funny noise, it might suggest they have an active imagination. Pay close attention then to things that make your partner laugh next time you are spending time together!
The Role of Humour
Whatever the underlying mechanism of humour, it is likely a trait that has been selected for by evolution. Laughter has been shown to help improve immune and central nervous system performance and to help us cope with difficult circumstances (3). It is also a powerful tool for aiding social interactions, as we can bond over a shared joke and use it to help calm other people down during a stressful situation.
In his book ‘The Mating Mind’, Geoffrey Miller suggests that a sense of humour might have been indicative of other desirable survival traits such as intelligence – which might explain why many jokes can be seen as almost riddle-like.
It’s also very possible that we ‘learn’ laughter as a response and are encouraged by others to laugh. While in some cases we laugh genuinely, it may be in other cases that we laugh because it demonstrates that we understand – not because we really find something funny. This could be the case very often when it comes to puns…
So the good news is that humour has so far proven somewhat impervious to close scrutiny and remains at least broadly mysterious. What we can say though, is that humour is often the result of a computational incongruence, schadenfreude (appreciation of the suffering of others) or of a sense of relief. We know that the ‘understanding’ of a joke takes part in the brain areas responsible for higher understanding too, but the ‘magic ingredient’ nevertheless remains as elusive as it is subjective.