The Penguin Dictionary of Psychology has become a byword for demystifying the language of this complex subject. Now fully updated for its fourth edition this wide-ranging and accessible dictionary is invaluable for both students and professionals and an indispensable guide to all areas of psychology and psychiatry. It covers related fields such as neuroscience and social psychology. It describes how terms are employed their wider connotations and past usage. It looks in detail at such key concepts as addiction and instinct.