Why is Laughter Contagious?
June 2012 - Why does one person pick up another's emotions so easily? It seems that human emotions are highly contagious. For example, one person's laughter is soon shared by another's. The explanation is that strong emotions synchronize the brain activity of different individuals according to research by Finland's Aalto University and Turku PET Centre research published in the Proceedings of The National Academy of Sciences
Seeing emotional expressions such as smiles and laughter in someone else often triggers a corresponding emotional response in the watcher. This may be a basic element of social interation: synchronyzing a common emotional state in all members of a group whose brains process what they see of the environment around themin a similar fashion.
The Finnish researchers measured brain activity with functional magnetic resonance imaging while participants were looking at short pleasant, neutral and unpleasant movies.The researchers found that strong and unpleasant emotions synchronized participants brains' emotion processing networks in the frontal and midline regions while highly arousing movies synchronized activity in brain networks supporting vision, attention and sense of touch.
According to Adjunct Professor Lauri Nummenmaa from Aalto University:
"Sharing others' emotional states provides the observers a somatosensory and neural framework that facilitates understanding others' intentions and actions and allows to 'tune in or syncwith them. Such automatic tuning facilitates social interaction and group processes.
"The results have major implications for current neural models of human emotions and group behaviour, but also deepen our understanding of mental disorders involving abnormal socioemotional processing.