Are we so impressed by the power of collaboration that we've come to overvalue working in groups, asks Jock Given in his review of the books 'Quiet: the power of introverts in a world that can’t stop talking', by Susan Cain, published by Crown Publishing, New York, 2012, and 'The Master: a personal portrait of Bart Cummings', by Les Carlyon, published by Pan Macmillan, Sydney, 2011.