An undesirable condition in which all members of a group (e g a project team) begin to think alike or pretend to think alike No members are then willing to raise objections or concerns about a project even though they are legitimate and based on hard data
a group process in which group members work so hard to achieve unanimous agreement that they fail to consider realistically the various alternative courses of action available to them
is 'a mode of thinking that people engage in when they are deeply involved in a cohesive in-group, when the members' striving for unanimity overrides their motivation to realistically appraise alternative courses of action' (Janis, 1972)