“Sharing any emotions – especially the bigger ones like sadness, anger and happiness – allows our friendships to blossom. In fact, we forge a bond far stronger than if we both chat about watching the same TV shows over the weekend. So we can end up feeling emotions for others, as well as our own.”

Of course, it’s easy to assume you’re being self-indulgent if you find yourself feeling low on another’s behalf; after all, the sadness-inducing event is not happening to you directly, so why on earth are you behaving as if it is?

McMahon, however, says secondhand sadness is only ever considered a selfish act if you are going to other people for sympathy of your own. “It’s more likely that you are an empathetic person,” she says. “But sometimes, when we accidentally confuse sympathy and empathy we can end up really feeling that emotion with someone, rather than understanding how they feel and recognising the challenge it brings for them, not us. And this can really affect our own mental wellbeing.”

Secondhand sadness: what to do when other people’s bad moods affect you