The incidence of autism spectrum disorders has increased dramatically over the past two decades, yet these disorders are still poorly understood. By considering the viewpoints of autistics themselves, together with evidence from the scientific literature, it becomes clear that autism spectrum disorders are not always the debilitating conditions…

Contents of this symposium comprises: Introduction (W. B. Dockrell); The Genetics of Intelligence (Sir C. Burt); Structuring Mental Acts (P. R. Merrifield); A "Piagetian" Test of Cognitive Development (R. D. Tuddenham); The British Intelligence Scale (R. W. Warburton); Intelligence (P. E. Vernon); Hierarchical Theories of Mental Ability…