Being a member of a team can inspire and motivate people to work hard, but both research and practical experience have shown that some team members don't contribute fully to the team. This reduction in effort caused by motivation losses is described as social loafing. It is relatively clear that social loafing has the potential to reduce the likelihood of an athletic team's success. This book reviews and analyses the phenomenon of social loafing in a sport context, and in relation to different group dynamic variables.