We learn to laugh before we speak or walk. Sharing a joke brings people together, creates friendships, and helps us to cope with even the bleakest of times. But what exactly is going on when we laugh?
What is laughter exactly?
Laughter is a non-verbal vocalisation that is a response to something in our environment, or to a thought or memory. It can express that we find something funny, or that we are relieved, or sometimes that we’re scared or nervous.
Laughter starts in our limbic system - which means that laughing is involuntary, we don’t choose to laugh. When the limbic system gets a message from the part of our brain that decodes visual and auditory information (the frontal lobe) telling it we need to laugh, the limbic system then sends out a message. This sets a physical process going, and gives our diaphragm, intercostal muscles and 15 facial muscles a good workout.
Is laughter just a human thing?
Research suggests that laughter is not just for humans.
Charles Darwin himself noticed how pet dogs tease their owners. Apes engage in social play and tickle each other. Apparently even rats laugh!
Because we see laughter occurring in other animals, it’s likely that it had an evolutionary role for us. At some point in history, laughter might have helped us to survive.
The evolution of laughter could be linked to the survival of the group - the ability to make people feel at ease and part of a community made a group stronger and contributed to its success.
When did humans start to laugh?
There are two types of laughter - neurologically speaking. The first is Duchenne laughter, which is an emotional response to stimuli that we see starting with preverbal babies. It is thought that Duchenne laughter became a kind of social glue in our human ancestors between four and two million years ago.
The second is non-Duchenne laughter, which is more voluntary and is controlled by a different part of the brain. This kind of laughter appeared when humans developed more sophisticated cognitive abilities. These two kinds of laughter have distinctly different processes in the brain.
What is the world’s oldest joke?
Jokes require quite complex cognitive processes. We need to be able to understand and picture other people’s perspectives, be able to predict other people’s reactions, and play with those expectations. And we often have to understand many things that are un-said to do with social rules, norms and language so we understand when a joke violates them.
For the purposes of discovering the oldest joke in the world, a joke is defined as having a clear set-up and punchline structure.
The Guinness World Record for the world’s oldest joke goes to a Sumerian proverb dating from 1900 BCE and it’s the kind of thing kids today would still find funny - it’s a fart joke.
Sumerian is one of the world’s oldest languages. It’s from ancient Mesopotamia (modern-day Iraq). The joke was found on a tablet from the Old Babylonian period and may date back as far as 2,300 BCE.
Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap.
Is laughter really the best medicine?
The ancient Greek philosophers thought that laughing at others or at earlier versions of ourselves served to make us feel superior.
Freud theorised that laughter was used as a release for pent-up nervous energy, which led to a later theory to do with the resolution of incongruity, meaning that ultimately, we laugh because we have seen something in a new light.
Laughing increases our oxygen intake and releases endorphins, which can create the effect of easing pain. It can also lower adrenaline and cortisol levels, which reduces our feeling of stress, and floods our bloodstream with feel-good dopamine and oxytocin.
By strengthening our brain’s neural connections, it can also improve our mood.
That’s not all. Laughing can be credited with helping us lose weight, well, a very tiny bit of weight - laughing for 10-15 minutes can burn up to 40 calories. Some studies show that people who have just been laughing can withstand 15% more pain, and there are all sorts of laughter therapies available.
So, it might not be the best medicine definitively, but it’s certainly beneficial!