The first edition of Autism: Explaining the Enigma quickly became a classic because it provided the first satisfactory psychological account of what happens in the mind of a person with autism. The book proposed that the key problems were an inability to recognize and think about thoughts (theory of mind), and an inability to integrate pieces of information into coherent wholes (central coherence). It suggested that from this beginning, problems of communication, social interaction, and flexibility follow as the complex interactions of human development unfold. This updated edition reports on how this explanation has stood the test of time. A new chapter outlines developments in neuropsychological research that have taken place since the book was first published and reviews the growing body of work on the neurological basis of autism. The accessible style and structure of the original edition have been retained, with information and references updated throughout.