Does your way of laughing change depending on who you are with?
Although the origins of our sensitivity to laughter can be traced back millions of years, this is a skill that is still relevant to us today. As viewers, how well can we use the sound of laughter to infer the nature of relationships?
The quantity and quality of laughter between two people can potentially tell us a lot more than just sharing a joke. For example, friends laugh more than strangers, and shared laughter can be an indicator of sexual interest between a couple. But as viewers, how well can we use the sound of laughter to make these kinds of inferences? A study published in PNAS is the first to investigate these dynamics; it would appear that regardless of our culture, we are good enough at using laughter to identify the nature of other people’s relationships.
The researchers asked pairs of English-speaking American college students to come into the lab and talk about various topics, such as “bad experiences from roommates.” Both people wore microphones, through which their laughter was recorded. Basically, some of the pairs of people were good friends and some of them were strangers who only met that day (Bryant et al., 2016).
The researchers then took these audio recordings and extracted moments of “colaughter” between the couples: that is, those times when both people started laughing within a second of each other (Bryant et al., 2016) .
Participants recruited from around the world were then asked to listen to these short clips and try to figure out (by listening to the moments when they laughed) whether it was a couple of friends or strangers. There were 966 listeners from 24 countries on five continents, including India, Namibia, Peru, and Slovakia (Bryant et al., 2016).
Listeners were able to judge whether the laughter clips came from friends or strangers with a reasonable degree of accuracy – they got it right 61% of the time, which statistically is significantly different than if they had just guessed. Listeners were most likely taking advantage of the fact that the way we laugh with our friends sounds different than the way we laugh with strangers, including a shorter amount of time for each burst of laughter, more erratic pitch and volume. Surprisingly, the ability of listeners to judge which couples were friends and which were strangers was very similar across cultures, including those unfamiliar with English. It doesn’t matter where you come from: it seems that laughter is a language we all understand (Bryant et al.,
This ability likely evolved because identifying the relationships of others at a distance was beneficial to our primate ancestors. For a stranger, it is helpful to recognize that two individuals are close to each other – it could signal that this is a close group worth joining, or if that is not possible, that the couple poses a greater threat because they are closely allied (Bryant et al., 2016).
Confirming this idea that human laughter has deep evolutionary roots, a previous study involved researchers tickling young orangutans and gorillas: the noises they made were similar to the sound of human infant laughter (Bryant & Atipis., 2014).
Although the origins of our sensitivity to laughter can be traced back millions of years, it is a skill that is still relevant to us today. Imagine starting a new job and trying to understand the relationship between others in your office. Just as you will be attuned to other people’s body language and the content of their speech, you will likely infer information from the way they laugh at each other. But remember, it works both ways. So the next time you forcefully laugh with a colleague or acquaintance, don’t forget: for reasons that go back to your primate ancestors, someone who is watching you or the interlocutor himself may discover you (Bryant et al., 2016).