How did the brains of our hominin ancestors first become human minds? When did our capacity for language and art, music and dance evolve? And why does this matter today? This groundbreaking book contends that it was the need for early humans to live in ever-larger social groups, and to maintain social relations over ever-greater distances – the ability to ‘think big’ – that drove the enlargement of the human brain and the development of the human mind. As Thinking Big shows, it seems we still inhabit social worlds that originated deep in our evolutionary past – by the fireside, on the hunt and across the grasslands of Africa.