Why do some teams perform great, while others get stuck in mediocrity? In the AD article by neuroscientist Chantal van der Leest, we dive into fascinating group phenomena such as social loafing and the Ringelmann effect: the more people in a team, the less everyone does. What makes a team really effective? And why is a team of five often better than one of thirty? With insights from psychology, practical experience with organizations such as Buurtzorg, and tips for better cooperation, this article is a must-read for anyone working in or with teams. Discover how to recognize and break through group behavior.