Why do we clap?

At the Cannes Film Festival, standing ovations can last for more than 10 minutes. It begs the question: what drives human beings to smack our hands together to applaud?

There's long, and then there's the standing ovations of the Cannes Film Festival. After Horizon: An American Saga screened there recently, the audience clapped for seven minutes. And that's not even the longest ovation in the festival's history. That prize goes to Pan's Labyrinth in 2006, after which the applause lasted a staggering 22 minutes.

When I heard about this, I couldn't resist giving it a try: a proper Cannes-length ovation. What is it like to applaud for that long? I wasn't even sure I could manage it. So, this morning, I asked my daughter to start a timer, and I started clapping.

"Why are we doing this, Dad?" she asked as the minutes ticked by.

Not knowing what else to say, I could only reply: "It's for science."

Sixty seconds in, and things were going well. "This is easy," I thought. "I could do this forever!"

Soon though, I started to question things – my choices in life, how I got here – but mostly: why do we clap at all? Why did people first start bashing their palms together to show appreciation? Do other animals do it? And why don't we – or indeed Cannes audiences – do something else, like honk, whistle, or click?

Homo sapiens probably started clapping early in our history, writes psychologist Alan Crawley in a 2023 review of research on the topic. Our primate ancestors may not have screened movies, but in the absence of spoken language, they may have realised they could use the noise to signal the presence of predators, to intimidate opponents, for play, or to highlight opportunities.

In the present day, some primates have been observed using clapping to direct the attention of their peers, or to communicate over long distances. Wild grey seals do it too, while underwater, to show strength and dominance to mates.

…and my clapping experiment draws the attention of my dog, who I realise lacks the limb orientation to clap. If I spoke dog, I could explain to him that I'm embarking on an important exploration of human socio-cultural norms, but I can't – so he starts to bark at me.

It's unclear exactly when people started clapping to show appreciation for performance – applause. It's mentioned in the Bible a few times, as a way to rejoice or worship. The Ancient Egyptians may have done it too.

However, the practice of crowds applauding theatre or speech appears to have fully taken off in Ancient Rome. As the video from BBC Ideas explains below, plays would contain the word "plaudite" at the end of scenes, the root of the word "applause":

For Roman leaders, clapping was also an audible measure of popularity, akin to an approval poll or social media likes. Some paid to make the applause louder: Nero apparently shelled out to get 5,000 soldiers to do so at his appearances.

The hired clapper returned in the 1500s, after a French poet offered free tickets to audience-members in exchange for loud applause. Throughout the following couple of centuries, professional paid "claquers" in France would attend performances to lead the ovations.

…and I'm questioning what I do for a living. My hands ache, and I regret wearing my wedding ring. I remember how actress Nicole Kidman was once ridiculed for clapping like a seal at the Oscars. She later explained it was to avoid bashing the rings on her fingers. Smart.

Clapping is simple to do. While observational studies suggest that babies aren't coordinated enough to clap until late into their first year of life, children can easily do it.

This may explain its prevalence across various cultures – especially compared with trickier acts like clicking your fingers – the chosen method of spoken word poetry audiences.

It also makes an effectively loud noise with low effort. "Clapping is par excellence, the non-vocal signal with the highest acoustic volume… and a simple, quick and effective action," Crawley observes. You could slap your hand against another part of your body, like your thigh, but the noise-to-effort ratio is less.

Finally, clapping is also perhaps more socially acceptable than screaming, honking or whooping. While the opera may tolerate such uncouth behaviour – with shouts of "bravo" or "brava" – clapping has the flexibility to be polite and light, as well as enthusiastic and protracted.

For example, the movement allows for variants like the "golf clap" – fingers to palm – which is designed to show quieter appreciation without distracting someone on the tee. 

…and my mind is wandering. Apparently it was around this point that actor Adam Driver lit a cigarette during a lengthy Cannes ovation in 2021. I decide not to: clapping while smoking is dangerous. 

Some researchers have pointed out that clapping can also signal more than appreciation alone: in some cases, it allows audiences to collectively mark transitions during a ritual event, as in: "the national anthem has now finished, let's watch some sport."

Crucially, it also can be an act that fosters social ties. For example, during the pandemic lockdowns, the practice of organised clapping at certain times of day was, on the surface, about showing appreciation for key workers. But it also arguably brought people closer together at a time of enforced separation, through a shared act of celebratory noise-making, belonging and unity.

It is occasionally socially frowned-upon, though. It's discouraged in the UK House of Commons, for instance, and pity the naïve person who claps between movements in a classical music concert.

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…and my daughter has had enough. "I'll come back later," she says, and goes to leave the room. "Wait!" I cry, but she's gone. They say the sound of one hand clapping is silence. When there's two hands, it's loneliness.

There's an element of social contagion to applause. Anyone who's sat in a crowd will know that a mere handful of clappers can sometimes trigger a room of people to mimic their behaviour. "Sometimes people clap because they want to send a message. At other times, people may clap not due to inner choice but rather social pressure," writes Crawley.

In 2013, a team led by Richard Mann, then at Uppsala University in Sweden, observed this happen after academic lectures. They found that the start of applause often followed a similar pattern to the way a disease spreads.

So why do we clap? The answer, in short, seems to be: it's the most effective way to make a lot of noise, show our appreciation, and strengthen the social bond that comes from enjoying something together. But what about super-long applause, à la Cannes? Why not just leave it at a minute or two?

Back in 2013, Mann told BBC News that the length of applause did not correlate with the quality of the performance. "You have this social pressure to start (clapping), but once you've started there's an equally strong social pressure not to stop, until someone initiates that stopping."

Applying this finding to the staggeringly long Cannes ovations, the conclusion would be this: no-one in the room wants to be seen – or in the social media age, filmed – as the first one to stop.

…and at this point, the sound becomes something alien and abstract. It's like my hands belong to someone else. I imagine the audience in Cannes who reached 22 minutes in 2006 and wondered what they felt: did they contemplate it continuing indefinitely, until they died? Did they reach some higher state of consciousness?

Myself, I never find out. I decide to stop before my hands go raw – and because I need to write this article. Still, I end my experiment knowing I had clapped continuously for longer than I ever had before. My daughter may not be impressed, but surely that deserves a round of applause? 

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