Mark Eys - Professor, Department of Kinesiology/Physical Education and Psychology, Wilfrid Laurier University, a former Canada Research Chair (2009-2019) and currently holds a Laurier Research Chair in Group Dynamics and Physical Activity. His current research interests include role perceptions in interactive groups, the measurement and correlates of cohesion, and the use of social influence to affect exercise behavior. Dr. Eys has published over 100 academic journal articles, 26 chapters, and two books including Group Dynamics in Sport (4th edition; co-authored), and Group Dynamics in Exercise and Sport Psychology (2nd edition; co-edited).