Many mammals – such as rats, dogs, chimpanzees, squirrel monkeys and other primate species – produce laughter-like vocalisations when playing with their peers. Laughter provides a unique perspective on vocal signalling behaviour because it plays a role in both one-on-one interaction and interaction among larger groups. Humans begin laughing soon after their birth, at the age of around three months. This is long before they start talking. Human laughter is universal. ‘One of the most interesting characteristics of laughter is its contagiousness,’ says Roza Kamiloglu, who is conducting the research together with her colleague Disa Sauter and five of their students. ‘But what does contagious laughter actually sound like and what makes one laugh more contagious than another? That’s what we aim to find out with our experiment.’

Join the laughter

Laughter has a range of social functions. It can serve to reduce tension between people, but can also be a way of bonding with others. By laughing along with someone else, you can show that you find this person attractive or pleasant or that you feel a bond with them. Kamiloglu explains: ‘In our experiment, we ask the participants to assess fragments of laughter on their level of contagiousness, on a scale from 1 to 5. We also ask them if they think the laugh was produced by someone from their own culture or a different culture.’

The researchers hope to gather a large amount of data, which will then enable them to identify and analyse the variability of contagious laughter. As part of this process, they will examine the acoustic characteristics of contagious laughter as well as the context in which contagious laughter occurs (for instance, when watching a comedy film or laughing at a joke) and demographic data, such as the sex and age of the laughing person. The experiment is being carried out in several languages: Dutch, English, German and Polish.

Want to get involved?

Go to the experiment website. You can rate as many laughter fragments as you like. The experiment will run until 1 February 2021.