IntroductionA leader is the key element that affects the overall success of the group by inspiring members to collaborate to achieve a common goal. The leader's approach to leading a group (i.e., their leadership style) plays an important role in the group's decision-making process and the quality of decisions. Effective leadership encourages member participation in the decision-making process and promotes cooperation and motivation among group members. On the other hand, ineffective leadership, lacking impartiality, can be a significant risk factor for groupthink; phenomenon refers to poor decision making and poor decision quality (Chapman, 2006). Groupthink is not desirable for groups because it harms the development of the group. In order to demonstrate the effect of leadership style on groupthink, the article will first explain groupthink and the factors that contribute to this phenomenon; then it will discuss the characteristics of different leadership styles and how they affect the group decision-making process; and finally, he will propose several remedies to guard against groupthink in groups.GroupthinkGroupthink, a term coined by social psychologist Irving Janis (1972), occurs when group members strive to obtain consensus at the expense of rational decisions. In other words, groupthink occurs in groups in which group members' desire for competition becomes more important than realistic assessment of problems and solutions (Chapman, 2006). Several factors contribute to groupthink, but the two most important are directive (i.e., promotional) leadership and lack of consideration of alternatives (Ahlfinger & Esser, 2001). If the group leader controls and promotes his preferred solution without consul...... middle of paper ...... plays an important role in the group decision-making process and affects the quality of decisions. Participative leadership emphasizes the participation of group members in the decision-making process for the highest quality and best solution, and encourages the productivity, creativity and motivation of group members. On the contrary, authoritarian leadership prevents alternative viewpoints from being considered and limits member contribution, which in turn increases the risk of groupthink, results in lower group productivity and performance, and leads to members of the unmotivated group. In order to avoid groupthink, three important factors must be considered: unbiased leadership, group synergy, and dialectical inquiry. Adapting these elements would prevent any group from making irrational decisions and promote collaboration, collectivity and high quality of group decisions..