The concept of GroupThink came to public attention for the first time to explain the disaster of the tentative to invade Castro's Cuba under President Kennedy (Bay of pigs invasion). None of the brilliant councillors of President Kennedy had dared to contradict him.
The psychologue Irving Janis was the first to try integrate the irrationality of our behavior in economics. He popularized the concept of GroupThink. GroupThink designates searching unanimity at any price.
GroupThink also generates a tendency of overbidding. Overbidding is the tendency to push the arguments which comply with the group philosophy to the extreme, thus neglecting any other important aspect
As per the original definition, GroupThink is « a mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members' strivings for unanimity override their motivation to realistically appraise alternative courses of action. » For more details as per Wikipedia: click here