Dr Jolyon (Jo) Maddocks has played an influential role in the development of psychometrically based approaches to the assessment and development of emotional intelligence. In conversation here with Rob Feltham, he provides a fascinating account of how the emotional intelligence concept originally captured the imagination of business leaders and rapidly became an integral part of business thinking. He discusses the part that he and his colleagues have played in taking assessment of emotional intelligence in fresh directions, with the focus on EI as being “a thing that you do” which is thus learnable and developable. Jo also talks about derailment, and the combined power of EI and personality assessment in understanding and predicting work behaviour and performance. Jo is Chief Psychologist for Developmental Products at Talogy. Prior to this Jo was co-founder of JCA occupational psychologists that he helped to grow into a thriving business over a 25-year period prior to its acquisition by Talogy in 2018. Over a 30-year career Jo has authored several widely used psychometric products and self-development programmes which have helped thousands of people develop their self-esteem, enhance their relationships and improve their performance at work. As a thought leader and experienced practitioner Jo has consulted with global organisations and government institutions. In 2018 he published the second edition of Emotional Intelligence at work: How to make change stick, and in 2019 completed his professional doctorate on an attitude-based model of Emotional Intelligence. Rob Feltham is Podcast Editor of The ABP.