---

The current construct of intellectual disability is based on the assumption that both IQ and adaptive behaviour can be measured accurately. Intellectual Disability explains how and why this is not fit for purpose and that it is actually neither necessary nor reasonable to have a single construct of intellectual disability.

---

1. History and Definitions 2. The Concept of Intelligence 3. Measuring Intelligence 4. The Concept and Measurement of Adaptive Behaviour 5. Acquiring a Diagnosis and the Prevalence of Intellectual Disability 6. Causes of Intellectual Disability 7. Problems with the Current Definition 8. Intellectual Disability Reconceptualised and Redefined

---

Simon Whitaker is Senior Visiting Research Fellow at the University of Huddersfield, UK, and Consultant Clinical Psychologist in Learning Disabilities in Huddersfield. His research interests include the reduction of challenging behaviour in people with learning disability, in particular anger and aggression, the measurement of IQ in people with learning disabilities, and the nature, definition and naming of learning disability.

---