JOHN COATES gave up running a derivatives desk on Wall Street to pursue studies in neurology and neuroendocrinology at Cambridge, where he is now a senior research fellow in Neuroscience and Finance. He and his team conducted a groundbreaking series of physiological experiments with traders in London to test his hypothesis that hormones aggravate, perhaps even create, cycles of boom and bust. The results, first published in Proceedings of the National Academy of Sciences, form the core of his first book. Coates was born and raised in Canada, and now lives in England with his wife and two sons.