Marc Lewis is an emeritus professor, neuroscientist, and developmental psychologist, interested in the emotional processes underlying psychopathology and addiction.
Career
Marc Lewis received his Ph.D. in applied psychology at the Ontario Institute for Studies in Education at the University of Toronto in 1989. He was supervised by Robbie Case and can trace his academic lineage back to Jean Piaget through Case's mentor Juan Pascual Leone. From this neo-Piagetian origin, Marc Lewis began investigating cognition-emotion interactions: the influence of cognitive development on emotional and personality development, and the influence of emotion on cognitive and personality development, as a professor at the University of Toronto. This early theory and research led Lewis to incorporate the dynamic systems approaches to development that were emerging in the early 1990s. Following the work of Esther Thelen, Paul van Geert, Alan Fogel, and others, Lewis developed an integrated account of development as self-organization at multiple time scales to explain both the stability and change of emotional aspects of personality. Through a sabbatical at the University of Oregon in 2000-2001, Lewis took the next step in developing his integrated model by delving into the neural underpinnings of emotion regulation. His research program over the next decade tested this model by examining brain and behaviour in normal and clinically referred children and assessing neural changes corresponding with developmental milestones, normal changes in identity and personality, and treatment outcomes for children with emotional difficulties. His papers on the contribution of dynamic systems theory and affective neuroscience to understanding human development and clinical syndromes have appeared in journals such as Child Development, Behavioral and Brain Sciences, New EnglandJournal of Medicine, and Perspectives on Psychological Science. He has also co-authored two books with his wife, . The first is an edited volume of The second is a guide for parents about when to attempt sleep training with toddlers. Lewis began his focus on addiction in 2009. His first book on addiction, ', connects his own years of drug use with an account of how the brain changes with various drugs and with addiction itself. In the second, ', biographies of addicts are linked with neuropsychological findings to show how addiction develops and how it can be overcome. Both books have been published in several languages, and Biology received the PROSE award for Psychology in 2016. Lewis currently writes for the popular press, maintains an active blog, sees online clients for consultation and psychotherapy, and speaks internationally on the science, experience, and treatment of addiction
Lewis' theory of emotional development relates multiple time scales using characteristics of self-organizing dynamic systems as causal mechanisms. This theoretical model relates the moment-to-moment emotional experiences in real time to the moods that persist for longer stretches at a middle or meso-time scale. These events consolidate through the strengthening or pruning of brain connections to become the habits and tendencies of personality at a developmental time scale of years. A further extension of this model incorporated the evolutionary time scale in an attempt to resolve the dispute about whether basic emotions are "natural kinds".
Theoretical Model of Addiction
Lewis' contends that addiction is not a disease, but rather a habit that self-perpetuates relatively quickly when people repeatedly pursue the same highly attractive goal. Addictive patterns grow quickly and become more entrenched because of the intensity of the attraction that motivates them, the layered symbolic value they acquire, and the loss of a sense of personal continuity and self-control over time. These psychological changes are mediated by changes in dopamine circuitry and prefrontal mechanisms of perspective-taking, self-concept and inhibitory control, accompanied by a narrowing of the relevant social world. Often, emotional turmoil during childhood or adolescence initiates the belief that addictive rewards are the only reliable sources of relief and comfort. Addiction is a neurally-entrenched phase of personality development, but neural plasticity allows for continuing growth and future wellbeing.
