Laughter has been lifting our moods and selling tickets for comedies for centuries. Although the act of laughing is well-understood by everybody, the science behind why we laugh is not as concrete. Recent research worldwide has shone a new light on laughter, why we do it and what other species do it. Here are five facts about laughter that you might not have known.
Laughter demonstrates friendliness towards others
Laughter can be a great ice-breaker in social situations, especially when talking with people you might not know. A 2010 study found that laughing and smiling are important ways of subtly showing kindness to others. (i)
Apes and humans use their facial expressions to communicate their lack of aggression towards other primates. Laughter helps us demonstrate goodwill better than other forms of smiling. A simple laugh involves the contractions of multiple muscles simultaneously, which can be very tricky to fake convincingly.
Most laughter is not humour-related
A professor of psychology and neuroscience at the University of Maryland, Robert R. Provine, described an interesting study about laughter. The study participants would eavesdrop on the conversations happening around them in their local shopping centres.
By the end of the study, the participants laughed 1,200 times, but only ten per cent of the laughter happened because of jokes. Robert Provine suspects that this happened because laughing is more about bonding than about comedy.
Animals laugh, but sometimes we cannot hear them
As mentioned earlier in the article, humans are not the only species that are capable of laughter. The exciting part about this fact is that we found it out by tickling animals in experiments.
In 2009, Marina Davila Ross carried out a study at the University of Portsmouth. The experiment involved tickling primates, including gorillas, chimpanzees and orangutans. Each ape laughed in response to the tickling, suggesting that our ability to laugh dates back to our primate ancestors. (ii)
Rats have also been tickled for science. Researchers at Washington State University found that rats will seek out and play with the researcher’s hands. When stroked, the rats made high-pitched giggling noises that can only be heard with the help of listening equipment. (iii)
Rats laugh quite a lot, in fact. The chirping-giggling noises they made when tickled are the same sounds they make during play with other rats.
Laughter is contagious
When people around you are laughing hard, it can be difficult not to crack a smile. The reason why laughter can spread is hardwired into our brains. A neuroscientist at University College London found that when she played audio of laughter to volunteers, the part of the brain responsible for preparing facial muscles to move lit up.
The sound of giggles activated the same part of the listener’s brain that deals with smiling. The research goes to show that infectious laughter is deeply rooted in our brain’s wiring. (iv)
It is in our genes
Our genes can make us more prone to specific interests or abilities. Still, recent research suggests that genes may even shape our sense of humour.
A study of more than 300 people in the USA found that people who have a specific form of the gene 5-HTTLPR were quicker to laugh at funny movie clips or cartoons. The short form, or allele, of the 5-HTTLPR gene is present in some people, whereas others have the extended version. The co-author of the study, Claudia M. Haase, said that people with short alleles may flourish in positive environments. Still, they might suffer in a hostile environment. “While people with long alleles are less sensitive to environmental conditions.” (v)
References
- Takeda, M., Hashimoto, R., Kudo, T., Okochi, M., Tagami, S., Morihara, T., Sadick, G. and Tanaka, T. (2010). Laughter and humor as complementary and alternative medicines for dementia patients. BMC Complementary and Alternative Medicine, [online] 10(1). Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2896339/ [Accessed 30 Apr. 2021].
- Davila Ross, M., J Owren, M. and Zimmermann, E. (2009). Reconstructing the Evolution of Laughter in Great Apes and Humans. Current Biology, [online] 19(13), pp.1106–1111. Available at: https://www.cell.com/current-biology/fulltext/S0960-9822(09)01129-4 [Accessed 30 Apr. 2021].
- Panksepp, J. and Burgdorf, J. (2000). 50-kHz chirping (laughter?) in response to conditioned and unconditioned tickle-induced reward in rats: effects of social housing and genetic variables. Behavioural Brain Research, [online] 115(1), pp.25–38. Available at: https://pubmed.ncbi.nlm.nih.gov/10996405/ [Accessed 30 Apr. 2021].
- Stafford, N. (2006). Laughter: it’s catching. Nature. [online] Available at: https://www.nature.com/news/2006/061211/full/061211-7.html [Accessed 30 Apr. 2021].
- Haase, C.M., Beermann, U., Saslow, L.R., Shiota, M.N., Saturn, S.R., Lwi, S.J., Casey, J.J., Nguyen, N.K., Whalen, P.K., Keltner, D. and Levenson, R.W. (2015). Short alleles, bigger smiles? The effect of 5-HTTLPR on positive emotional expressions. Emotion, [online] 15(4), pp.438–448. Available at: https://pubmed.ncbi.nlm.nih.gov/26029940/ [Accessed 30 Apr. 2021].
