Here’s what makes your emotions more infectious to others

Can your friend catch your bad mood, or can your partner infect you with happy one?

Picture credit: Harriet Nobel

Published: December 14, 2023 at 4:00 pm

If you’ve ever been in a jolly mood, with a spring in your step, then met up with a friend who is feeling grumpy, you’ll know how contagious emotions can be. Before you know it, you realise that you’re feeling down too. Happily, it can work the other way around too – when you’ve been sad, perhaps your friend’s bubbliness has helped to lighten your mood. 

Psychologists have shown that when people interact, a lot of mimicry goes on without us even realising it – from body language, to speech rate and pitch, to facial expressions. This is especially the case when we’re interacting with someone we know and care about.

A lot of these processes have to do with effective communication and mutual understanding. One way we make sense of other people’s feelings is to simulate those feelings in our own mind. The net result of this mirroring is that we can infect each other with our emotions. 

You might wonder who wins out – if you’re feeling happy and your friend is feeling sad, and you meet up, do you succumb to their sadness or do they catch your happiness? Part of the answer is likely to come down to their and your levels of expressiveness and receptiveness.

Everyone varies in how emotionally expressive and suggestible they are. If you smile a lot when you’re happy, you’re more likely to infect your friend. Likewise, if your friend is suggestible and more prone to facial mimicry, then they’ll be more likely to catch your smiles and start feeling happier (researchers in Germany showed that people who tend to mimic facial expressions are more prone to catching other people’s emotions).

That isn’t to say that facial expressions are the only way for emotions to spread. For instance, there’s evidence that fear has a smell, and that smelling the sweat of an anxious person can trigger activity in parts of the brain involved in empathy and processing emotions. 

In fact, for emotions to spread, there doesn’t need to be any physical contact at all. Researchers have shown that emotions can spread through social media. People who are exposed to more negative posts are more likely to go and post something negative themselves. 

Whether or not you find it grating to encounter an emotion opposite to the one you’re feeling will come down to the context. Generally speaking, it can be soothing to find we’re on the same emotional wavelength as others. Hence the popularity of listening to sad music when we’re feeling down, or the appeal of wallowing in heartache with a sympathetic friend. 

If and when you encounter an opposite emotion to your own, the experience will likely vary depending on how invested you are in that other person or people. If you care about them, you’ll be more motivated to make an emotional shift to match their state (research shows we’re more likely to mirror the emotions of people we like). Conversely, if you’re feeling sad and a bunch of strangers sit near you on the bus laughing their heads off, you’re likely to find it really annoying. 

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