Laughter really is in our DNA. The question is why.
Using old jokes and science, Edinburgh University professor of evolutionary ecology, Jonathan Silvertown, explores why laughter is our first language and what is certifiably funny and what isn't in his new book, The Comedy of Error: Why Evolution Made Us Laugh.
Many great thinkers throughout the ages have pondered the mysterious nature of laughing, what function it serves and why it is contagious, he tells Jesse Mulligan
“People have different styles of humour. People laugh even when there’s no joke involved. In fact, we laugh more often in ordinary conversation than we do in response to actual humour.
“So, over the years, serious thinkers like Hobbes or Kant, who were not known for their jokes, did actually think, why do we do this? What is the essense of humour?”
Each has come to a partial conclusion, but none saw the whole picture, he says. Silvertown contends that the advances of science, particularly evolutionary and neurological biology offer just this.
Babies laugh, as do animals. There exists an evolutionary history of laughing.
“They do it in social situations, so laughter long predates humour in our ancestry because it’s what behavioural scientists call a play vocalisation. So that is certainly undisputedly the origin of laughter… It’s shared by all social mammals in some form.”
Animals display ‘play vocalisation’ as a means of communicating they are at play, as opposed to being aggressive. It explains why the contagiousness of it is functional, a form of signalling that as social play is happening. “It’s a way of lowering the temperature of a social interaction.”
When we evolved language this signalling get more intricate and laughter at some point became associated with humour, which Silvertown estimates started one or two million years ago. Before language played a part, people were probably laughing at what we might now call ‘slap stick’ humour, with bodily movements or gestures provoking laughter.
“Apes will laugh when they throw poo at each other or us and think that’s hilarious. So, there’s no doubt toilet humour was one of the earliest forms of humour.”
Humour has evolved since the earliest records of it but show similarities. A joke book written in Latin from 400AD reveals derisory jokes about people the Greeks hated, which Silvertown says could be over 2000 years old.
“They’re about very similar things to what people laugh about today, especially if you forget political correctness – and I’m not suggesting one should – but they laughed at people who were fat, they laughed at slaves, they laughed at lawyers even who existed at that time.”
Humour is largely about trivial incongruity – a mismatch about what you think will happen and what happens, he says. Darwin wrote that humour is about non-threatening incongruity.
"Reinforcing this view is an experiment carried out in Taiwan with MRI scans. You can use this non-evasive technique to see which parts of the brain are firing up and it turns out that the incongruity hypothesis, which says, first you start with what might be called a set up – the expectation. Then you’ve got the punch line and in between you’ve got this crazy thing that connects the two together.”
The sequence causes a reaction in the brain that can be tracked with the scan, he says.
There is still an illusive thing that accounts of funniness. It’s a human reaction that depends on a number of factors, including context, knowledge and culture.
“What’s interesting though is it doesn’t matter which culture you’re in they all work the same why… the actual mechanism in the brain for everybody.”
Humour and making someone laugh seems to have sex appeal.
“Humour is always in there in the top-three things that people are looking for, in a partner for life,” he says.
Humour is also a demonstrator of intelligence too, because it requires fine judgment about what’s funny. “If you get it wrong, in a sense, you literally feel like a fool – the opposite of intelligent. So, it’s an extremely good indicator it would appear. Being funny is an advertiser of intelligence,” he says.
The human factor involved in humour and being funny is the reason artificial intelligence systems can’t replicate it. That mystery, the variables involved, has not been solved by the smartest computers.
Although, getting to the core of humour, dissecting it in a way, doesn’t take away its joy or unexpectedness, he says.
“There’s a certain type of romantic notion that some people hold, that the mystery of life actually makes it wonderful and if we know too much about it, it will no longer be mysterious. That’s most certainly not true. The more one learns about the natural world, the more marvellous it becomes and I think that’s true of jokes and anything else.”