This chapter explores the persistent relevance of groupthink in collective decision-making dynamics. It delves into the seminal work of psychologists Solomon Asch and Irving Janis, highlighting its enduring impact on various domains, including politics, the military, corporate boardrooms, and everyday meet- ings. Understanding the symptoms and consequences of groupthink is crucial for improving decision- making in contemporary society. Groupthink describes the tendency of closely-knit groups to prioritise consensus over rational decision-making, leading to hasty agreements without proper evaluation. The study emphasises the importance of constructive conflict, challenges the notion of conflict-free meetings, and explores strategies to mitigate groupthink, including fostering collaboration, appointing devil’s advocates, and promoting leadership that encourages open dialogue.