Groupthink

Group thinking is a state where the group's SON is unchallenged by criticism. It can be caused by group settings that inhibit any criticism on the group's SON, like excluding members that do not conform to the groups beliefs, or denouncing refuting evidences as illusions, heresy or efforts of some other rival ideology to break the group ideology.

Group thinking will cause the group to become conservative, and under influence of perceived danger may cause group polarization.