THE INFECTIOUS MIND is a gripping investigation into one of the strangest frontiers of human behaviour: how physical and psychological symptoms can spread socially – like viruses.  From the dancing plagues of medieval Europe to the ‘cat-concerts’ of seventeenth-century convents, from mass laughter in 1960s Africa to the Pokémon episode that reportedly hospitalised thousands, social contagion has shaped collective health and hysteria for centuries. Today, platforms like TikTok and YouTube are driving a new wave – from functional tics to dissociative identities – with symptoms that mimic those of others and spread at startling speed.  Drawing on history, neurology, psychology and culture, social scientist Matilda Gosling shows how our brains and bodies absorb the emotional currents around us, and how distress finds new forms of expression in each era. This is a book about why symptoms spread, why some become epidemics, and how we can protect ourselves in an age of mass connectedness.