What are the historical foundations of autism and what precisely is meant by the 'autistic spectrum'? How can we explain behavioural patterns of people with autism, young or old, and what are the major theoretical bases for understanding these? What is the latest thinking regarding diagnosis, and what are the most effective strategies for assessment, education and care for people with this condition? Following on from the popular provocative first edition, the Second Edition answers these questions with the latest research on autistic spectrum disorders, exploring theories at the psychological, neurobiological and 'first cause' levels to methods of assessment, intervention, education and support. Already popular as an introductory text for those wanting to know more about autism as well as a source of basic information and references for those familiar with the field, this newly updated and enhanced book is invaluable for students, professionals and even families.