Some interesting new research from Aalto University and Turku PET Centre finds that

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 ‘sync’ with them. Such automatic tuning facilitates social interaction.

I think an important implication of these findings for political and social movements is that positive, joint action can result from being “tuned-in” to each other, but this can also facilitate shared, mass delusions and beliefs. The research was described in Medical News Today:

Human emotions are extremely infectious. For instance, emotional expression like seeing someone smile often also triggers a smile in the person observing. These emotional synchronizations could be of help in social interactions. For example, if all members in a group share the same emotional state, their brains and bodies process the environment in a similar way. Researchers have now discovered that strong emotions can literally synchronize different peoples’ brain activities.

In their study, the researchers measured the participants’ brain activity by using functional magnetic resonance imaging whilst they were viewing either short pleasant, neutral and unpleasant movies.

The findings revealed that strong, unpleasant emotions in particular synchronized the frontal and midline regions of the brain’s emotion processing network, whilst highly stimulating events synchronized activity in those networks in the brain that were involved in attention, vision and sense of touch.

Observers who share other people’s emotional states become a part of a somatosensory and neural framework. This enables them to understand other people’s intentions and actions, allowing them to ‘tune in’ or ‘synchronize’ with them. Adjunct Professor Lauri Nemmenmaa from Aalto University states that this ability to automatically tune in enables social interaction and group processes.

Nummenmaa concludes stating that the finding is a key implication for current neural models of human emotions and group behavior, as it broadens the understanding of mental disorders with abnormal socioemotional processing.