In the study of social psychology, understanding group behavior is crucial for analyzing how individuals behave in social contexts. One phenomenon that often arises in groups is known as 'groupthink.' Groupthink can lead to poor decision-making because it discourages dissenting opinions and prioritizes consensus. In this situation, a group of colleagues is tasked with developing a strategic plan for their organization. After a lengthy discussion, they quickly agree on a plan without critically evaluating alternative strategies. This scenario exemplifies the effects of groupthink, but what is the primary psychological mechanism behind this phenomenon?