Ralf Schwarzer1,2,3, Edward McAuley4,5,6,7. 1. a Institute of Positive Psychology and Education, Australian Catholic University , Sydney , Australia. 2. b Department of Clinical, Health, and Rehabilitation Psychology , University of the Social Sciences and Humanities , Warsaw , Poland. 3. c Department of Psychology , Freie Universität Berlin , Berlin , Germany. 4. d Department of Kinesiology and Community Health , University of Illinois , Urbana , IL , USA. 5. e Department of Psychology , University of Illinois , Urbana , IL , USA. 6. f Department of Internal Medicine , University of Illinois , Urbana , IL , USA. 7. g The Beckman Institute, University of Illinois , Urbana , IL , USA.