Of Guffawing Uncles and Laugh Tracks: Why Laughter Is Contagious

This World Laughter Day, let’s see why you can’t help but giggle when you see someone laugh, without knowing why.

For representational purposes. (Photo: iStock)

Once Santa and Banta (or Chintu and Bablu, whatever floats your boat) were laughing at a party. Their friends saw them and started laughing as well. Soon, there were 15 people laughing together. But none of them knew what they were laughing at.

Ha, tricked you. This wasn’t a Santa-Banta joke but there’s a reason why those people started laughing without knowing what’s so funny.

This World Laughter Day, let’s see why laughter is contagious.

(GIF Courtesy: Giphy.com)

Sophie Scott, a neuroscientist at the University College London, where a study was conducted on the phenomenon, said:

We’ve known for some time that when we are talking to someone, we often mirror their behaviour, copying the words they use and mimicking their gestures. Now we’ve shown that the same appears to apply to laughter, too – at least at the level of the brain.

As social animals, we often respond to authentic laughter by laughing ourselves. This is why sitcoms have laugh tracks; hearing other people laugh is more likely to make us find something funny and laugh as well.

This is also why laughter sound tracks are typically recorded during live events – the laughter has to sound real or we won't join in.

The laughter groups in parks that your neighbourhood uncles go to also work on the same principle; when you see many people laughing, you involuntarily end up laughing too.

(GIF Courtesy: Giphy.com)

The way a person reacts to a sound is dependent on the brain’s premotor cortical region. This region is responsible for how the muscles in the face react to corresponding sounds. University College of London conducted a study on certain volunteers where they played different sounds to them and measured their brain’s reaction to the sound.

It was seen that responses were higher for positive sounds, such as laughing, and were much lower for negative sounds like screaming or retching.

This suggests that humans are more susceptible to the sound of laughter as compared to negative sounds. This explains the reason for our involuntary smile when we see other people laughing.

So, the next time you see someone talking on the phone in the metro and laughing loudly, don’t feel weird if a giggle escapes you; it’s not you, it’s science.

I’ll leave you with this video of laughter spreading through a train and it’s quite likely to make you laugh.

(With inputs from Psychology Today.)