JONATHAN WILLIAMS is a Principal Clinical Psychologist with NHS Wales. He has two decades of experience specialising in Intellectual Disabilities and has a particular expertise in ACT and related approaches, with a range of journal articles in that field. He sits on the UK and Ireland committee for the Association for Contextual Behavioural Science (ACBS), and he is also a national committee member of the BPS Faculty for People with Intellectual Disabilities. ROBERT JONES is Honorary Professor of Clinical Psychology at Bangor University, UK, and a retired Consultant Clinical Psychologist. He was formerly Programme Director on the Bangor Clinical Psychology Training Programme and has held various senior positions in academia and the NHS over several decades. He is the author of over one hundred peer reviewed publications and several books.