Sophie Scott, Professor of Cognitive Neuroscience at University College London, asks why we laugh, what it means and argues that it’s time to take laughter more seriously.
Laughter is something that humans closely associate with jokes and comedy. In fact, the late psychologist Robert Provine found if you ask people about what makes them laugh they talk about humorous materials like TV shows and comedians. However, Provine also found that if instead of asking people what makes them laugh, you simply watch them out and about and note when they laugh, then it quickly becomes apparent that laughter is primarily a social behaviour. We laugh when we are with other people. Provine found that we are 30 times more likely to laugh when we are with other people than when we are on our own. And most of the time we are not laughing at jokes and comedy – people laugh to make and maintain social bonds, to show agreement, affiliation, understanding and recollection. Indeed adult humans use laughter in incredibly nuanced ways – we will use laughter to try and manipulate or manage social situations, and we will use laughter to mask other emotions – like fear or sadness – which we may be trying to actively mask.
What is laughter?
Laughter is a non-verbal expression of emotion, and that means that it is highly unlike speech or song. In fact, it is more like an animal call than it is like speech, and it shares this characteristic with other non-verbal expressions of emotion, like screams or sobs.
We produce laughter largely at the rib cage, where large, fast contractions of the intercostal push air through the vocal tract at high pressure. The repeated contractions lead to each individual “ha” burst of the laughter, and if the contractions run into each other, the laughter becomes a longer noisy spasm. The pressures generated – especially when people laugh helplessly – can be much higher than those generated during speech or song, and consequently some very strange noises can be generated. Certainly when I laugh hard, I have a very high-pitched laugh, far higher than I could sing.