He is emeritus professor of applied psychology at Maastricht University, former dean of the School of Psychology & Neuroscience, former professor of health education & promotion, and former endowed professor of HIV prevention and health promotion; all at Maastricht University. His research and publications focus on applying psychological theories to behavior change to reduce societal problems, and on planning models for behavior change interventions for health promotion and disease prevention, energy conservation, traffic safety, and discrimination. He is one of the authors of the Intervention Mapping protocol (ISBN-13: 978-1119035497), stressing the importance of the optimal application of evidence and theories in health psychological research, intervention development, and implementation.