David D. Clarke is Emeritus Professor of Psychology, and former Head of School, at the University of Nottingham, UK. He holds doctorates from the Universities of Oxford and Cambridge and has taught at both. Having started his career in medical sciences, he mainly researches pathways into and out of dangerous situations including road traffic collisions, evacuations, fights, relationship breakdowns, and mental disorders. He is a Fellow of the British Psychological Society, and a Chartered Psychologist.

Dr Jill Collett (was Crossland) works as an executive leadership coach and business psychologist. She specialises in working alongside senior leaders as they build organisational cultures that are purpose driven, happy, inspiring places to work that have a positive impact on the systems within which they are embedded. Jill lives in Oxford with her husband and two daughters.