The Positive Sport and Peak Performance Lab is led by Professor Stewart Donaldson.


Josh Casillas, MA is a doctoral student at Claremont Graduate University, with a focus on Evaluation, Positive Organizational Psychology, and Public Health. He was a former All-Conference football player and his current research interests focus on optimal athletic development and performance.

Josh holds Master’s degrees in Counseling Psychology and Positive Organizational Psychology with a Co-Concentration in Evaluation and has taught as an adjunct professor on the topics of: Principles of Exercise & Sport Psychology, Applied Sports Psychology, Current Topics in Exercise and Sport Psychology, and The Psychology of Sport Injury Rehabilitation.

Lawrence Chan, MA is a PhD student in Organizational Behavior at Claremont Graduate University. He is currently a Lecturer at California State University, Pomona, College of Business Administration, People and Culture Consultant at FLOAT Shuttle, and Research Project Manager with Accenture, PLC. He is also the co-lab manager for the Positive Organizational Development Lab and Positive Sports and Peak Performance Lab under the supervision of Professor Stewart Donaldson, Department of Behavioral and Organizational Sciences. Prior to CGU, Lawrence completed his MA in Organizational Leadership at the University of San Diego, and his BA in Psychology at UC Riverside. Outside of academia, Lawrence enjoys staying active through surfing, rugby, and cross-fit, and playing hypo-competitive sports hyper-competitively.

Samantha MacDonald, MS is a PhD student in Positive Organizational Psychology at Claremont Graduate University. She is a co-lab manager for the Positive Sport and Peak Performance Psychology Lab and is beginning research exploring athlete wellbeing and the ties between positive psychology and sport. She has an MS in sport and exercise psychology, has conducted research surrounding the impact of athletic injuries, and has experience working with athletes and other performers on building mental skills aimed to improve performance and sport experiences.  Her background working with individual athletes and teams on improving and maximizing performance inspired the desire to incorporate positive psychology into mental performance interventions and shifting the focus to athlete wellbeing.