Sharing a cry over a sad film can strengthen connections between people – even if they are strangers, research has suggested.

Previous studies have shown reaching for the tissues while watching tragic films can boost levels of feelgood chemicals produced in the brain known as endorphins.

A new study, published in the journal Royal Society Open Science, suggests sharing emotions with others – while watching a comedy or a sad film – can also foster social bonds.

The team, led by Victor Chung of PSL University in Paris, recruited 112 people aged between 18 and 35 and split them into pairs.

Our results supported the hypothesis that emotion has a bonding function

The pairs, who did not know each other, were invited to watch emotional videos together as well as separately.

The researchers monitored their physiological and emotional responses, as well as how they felt towards each other after watching the videos together.

Results showed people felt more connected when they could see each other while watching the videos, and when they were both experiencing strong emotions, regardless of whether they were positive or negative.

In a follow-up online experiment involving 50 people, those taking part were asked to watch excerpts of French comedy Intouchables, the documentary Earthlings, which depicts the suffering of captive animals, and a YouTube video designed not to evoke strong emotions.

The team wrote: “Our results supported the hypothesis that emotion has a bonding function, as it could explain how brief one-shot interactions with strangers can contribute to satisfying the need to belong to social groups.

“The current study could also explain why people seek out group activities that induce intense and arousing emotions, even participating in sad commemorations or attending dramatic narrative fictions that induce negative emotions.”