Uncover the madness at the heart of society in this Sunday Times bestseller - now with a new introduction.

'The belly laughs come thick and fast' - The Observer 'Chirpy, inquisitive, funny' - Craig Brown

What if society wasn't fundamentally rational, but was motivated by insanity? This thought sets Jon Ronson on an utterly compelling adventure into the world of madness.

Along the way, Ronson meets an array of fascinating individuals, from psychopaths and those affected by madness to the experts tasked with diagnosing it. He learns the art of psychopath-spotting from the influential psychologist who developed the eponymous test, revealing that madness may lie at the core of everything . . .

Combining Jon's trademark humour, charm and investigative incision, The Psychopath Test is both entertaining and honest, unearthing dangerous truths and asking serious questions about how we define normality in a world where we are increasingly judged by our maddest edges.