Conscious control enables human decision makers to override routines, to exercise willpower, to find innovative solutions, to learn by instruction, to decide collectively, and to justify their choices. These and many more advantages, however, come at a price: the ability to process information consciously is severely limited and conscious decision makers are liable to hundreds of biases. Measured against the norms of rational choice theory, conscious decision makers perform poorly. But if people forgo conscious control, in appropriate tasks, they perform surprisingly better: they handle vast amounts of information; they update prior information; they find appropriate solutions to ill-defined problems.