Laughter does not wait for the joke

The American researcher Robert Provine devoted part of his career to a modest method: noting, in public places, what precedes a burst of laughter. His records, gathered in a book published in 2000, contradict the image everyone has of their own laughter.

Most laughs followed banal remarks, a greeting, a practical question, an observation with no wit to it. Only a minority responded to anything that might have been called funny. Another unexpected finding: the person speaking laughs more than the person listening.

These records suggest that laughter serves the relationship first. We laugh far more in company than alone, and laughter punctuates speech without interrupting it: it falls in pauses, at the end of sentences, rarely in the middle, like an audible punctuation of the exchange.

It signals a state of the relationship more than a judgement on what has just been said: I am well disposed, I do not take this as an attack, we are on the same side. This function explains why a laugh can be polite, conciliatory or embarrassed without being false.

Researchers commonly distinguish spontaneous laughter, which partly escapes control, from laughter produced deliberately. The two do not sound exactly the same, and listeners manage to tell them apart above chance, without succeeding every time.

Work with listeners from very different societies has shown that from a few seconds of recording, people can guess above chance whether two people laughing together are friends or have just met. Shared laughter carries information about the relationship itself.

Laughter is one of the most contagious behaviours there is, something the canned laughter of television programmes has long exploited. Hearing laughter predisposes us to laugh, which supports the idea of a signal intended first of all to attune the members of a group.

This contagion is nothing like a universal reflex. Laughter perceived as mocking, or directed against oneself, produces the opposite effect and pushes away instead of drawing closer. The same sound can include or exclude depending on the position of the person who hears it.

If laughter is relational first, it says little about humour. Someone who laughs little in meetings is not lacking in it for all that, and someone who laughs a lot does not necessarily find everything funny. Each person simply sets this signal of agreement in their own way.

Both settings have their returns. Frequent laughter smooths exchanges and defuses tension; it can also mask a real disagreement. Rare laughter gives more weight to each occurrence, and leaves the other person less certain of the reception they are getting.

Reading other people's laughter as a message about the relationship, rather than as a verdict on what one has said, corrects a common error: believing oneself funny when one is merely well received, or badly received when the other person simply laughs less.