There is one more danger of groupthink and that is, it inevitably leads to an 'us' vs 'them' situation. Irving Janis (who coined the term) proposed groupthink

There is one more danger of groupthink and that is, it inevitably leads to an 'us' vs 'them' situation. Irving Janis (who coined the term) proposed groupthink as a small group dynamic. Yet the collective shifts in perceptions towards target groups and group goals that occurred in Germany, Rwanda or Cambodia are clear examples of groupthink at a national level. The groupthink spreads, becoming a national dogma with an unchallenged world view or view that defines reality. Human brains have a lot of bugs!