The process of 'Groupthink' was discovered by:

I. Janis

The correct answer is Option (4) → I. Janis

" Generally teamwork in groups leads to beneficial results. However, Irving Janis has suggested that cohesion can interfere with effective leadership and can lead to disastrous decisions. Janis discovered a process known as “groupthink” in which a group allows its concerns for unanimity. They, in fact, “override the motivation to realistically appraise courses of action”. It results in the tendency of decision makers to make irrational and uncritical decisions. Groupthink is characterised by the appearance of consensus or unanimous agreement within a group. Each member believes that all members agree upon a particular decision or a policy. No one expresses dissenting opinion because each person believes it would undermine the cohesion of the group and s/he would be unpopular. Studies have shown that such a group has an exaggerated sense of its own power to control events, and tends to ignore or minimise cues from the real world that suggest danger to its plan. In order to preserve the group’s internal harmony and collective well-being, it becomes increasingly out-of-touch with reality. Groupthink is likely to occur in socially homogenous, cohesive groups that are isolated from outsiders, that have no tradition of considering alternatives, and that face a decision with high costs or failures. ..."