The Science of Laughter
What happens in your brain when you get the giggles?
People laugh about five times in every 10 minutes of conversation. They are also 30 times more likely to laugh when they are with other people compared to when they are alone. It’s common to think of laughter as a loud reaction to a funny joke, but most of the time it’s simply a recurring feature of normal social interaction.
Sophie Scott is a scientist and professor at University College London who leads much of the current research about laughter. Interestingly enough, she says, “most of the laughter you produce is not helpless” but rather the result of a voluntary act.
Laughter comes in two shades: voluntary and spontaneous. Voluntary laughter is the social lubricant that helps a conversation run smoothly, while spontaneous laughter erupts following a particularly humorous remark. Each form uses a different network in the brain. Voluntary laughter typically features more activity in frontal and motor areas of the brain associated with action planning and language. Spontaneous laughter includes greater activity in deeper structures such as the hypothalamus, which regulates basic physiological processes like hormonal balance.
Humans aren’t the only species to express these two types of laughter. Chimpanzees demonstrate a similar pattern, using more controlled laughter to join in with the giggles of other chimpanzees, and distinct spontaneous laughter in response to amusing events during play. The more chimpanzees laugh together, the longer they play together, especially when that laughter is social rather than spontaneous.
People are fairly good at distinguishing spontaneous from voluntary laughter. In one experiment from 2019, researchers tested whether hearing laughs after a joke would make it funnier. In essence, they were testing the psychological effects of the laugh tracks found in such American comedies as Seinfeld and Friends. People in the study rated jokes that were followed by laughter as funnier than those followed by silence, supporting the idea that laughter is driven by social situations rather than a joke’s content. It’s important to note that spontaneous laughter amplified humor ratings more than voluntary laughter did.