Laughing at a good joke or when someone tickles us is instinctive, but crying when we’re sad is something we learn from other people, say scientists.
They say that only expressions of laughter and relief are instinctive, whereas other emotional outbursts need to be learned.
To find out which sounds are instinctive, a team led by Disa Sauter in Nijmegen, the Netherlands, asked eight deaf and eight hearing individuals to vocalise nine different emotions, but without words.
These included fear, relief, anger, hilarity, triumph, disgust and sadness.
It turned out that the only two easily identifiable emotional sounds made by the deaf participants were laughter and sighs of relief.