There is a moment most people recognize: you intended to respond calmly and find yourself erupting. You planned to be generous and discover you are withholding. You decided to assert yourself and hear yourself apologizing instead. You prepared the rational, measured reply and what came out was something you barely recognize as your own voice. These moments feel like failures of self-control, lapses of will, occasions when the person you are supposed to be temporarily lost control to something less disciplined. What they actually are is something more interesting and more structurally significant: the moment when a complex seized the...