In this week of festivities, pageants and patriotism on the one hand, and protests, Uncut street parties and stark republican sentiments on the other, it is impossible not to be strikingly reminded how powerful our sense of allegiance is to groups, belief systems and ideologies, and how central passions and emotions are in such processes, with reason often having very little part to play. An interesting Finnish study has just been published  which demonstrates in a dramatic way what we have known already from other sources. We are a group species and emotions are central to this groupishness.. This study looked at the brains of people who viewed similar emotional events, such as in a movie. They found that feeling similar things can literally lead to the synchronisation of brain regions in groups of people. They derived what are called multisubject voxelwise similarity measures. intersubject correlations (ISCs)] of functional MRI data, which showed 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. It was found that observers who share other'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 each other. A key researcher in this study, Professor Lauri Nemmenmaa from Aalto University, argues that this ability to automatically tune in enables social interaction and group processes.
This study can be linked to many others about group processes. We tend to synchronise our body movements with those around us who we like and value. Singing together gives rise to group bonding, we know for example. One of the best predictors of health and longevity is the ability to join groups and to feel a sense of belonging. Even infants prefer to hear their own language and dialect, and the faces of those in their own racial and cultural groups, and are learning in the earliest months how to fit in to the world they happen to have been born into. We only have to watch football supporters to know the passion of bonding with ones in-group, and distrust of out-groups. E.O. Wilson , founder of the now less fashionable socio-biology, has just published an important new book about evolution in which he makes a strongly argued case for what is called group-level selection. This is the idea that altruism, helping each other, group loyalty and good feelings for ones in-group have been powerful evolutionary forces. While there can be competition within groups, as one group competes with another then in-group processes become more central, and strong groups with loyal members who looked after each other were the ones which thrived. Groups of selfish egoists would have fallen by the wayside in the evolutionary competition stakes.
As ever the paradox of humans is that the driver of our best traits, such as generosity, kindness, altruism, empathy and loyalty, our groupishness, is also the driver of some of our worst traits, such as the ability to favour our own over ‘different’ kinds of people, to dehumanise those who are ‘other’ and to show unfair preferential treatment to those who are known. Oxytocin, the ‘cuddle hormone’, is released when we are with people we like, it helps empathy, understanding other minds, trust and lowers social fear, but it also predicts an increase in suspicion of out-group members. Joining together is great for us and those we join with, and needs to be celebrated, as long as we caste a thought for those who we do not join with or who do not join with us.
 L. Nummenmaa, E. Glerean, M. Viinikainen, I. P. Jääskeläinen, R. Hari, and M. Sams, ‘Emotions Promote Social Interaction by Synchronizing Brain Activity Across Individuals’, PNAS, May 2012.
 E. O. Wilson, The Social Conquest of Earth. W. W. Norton & Co., 2012.