Digby Tantam presents his ground-breaking theory of the interbrain, the idea that human beings are endlessly connected by a continuous interplay of non-verbal communication of which we are unaware. Considering social smiles and the way emotions can spread from one person to another, he explores the research that shows how our brains are linked and draws out the implications of the interbrain for our understanding of empathy, social communication, psychology and group behaviour. Exploring this often overlooked aspect of our human nature, Tantam demonstrates how the interbrain has huge significance for psychology, psychiatry and sociology and can transform our understanding of war, morality, terrorism, psychopathy and much more.