Sometimes tribal/"team sport" group dynamics keep employees inline too. Executives can foster an "us against the world" mentality that blinds workers to that which is obvious to everybody else. When in this mindset, people have the ability to ignore even the most damning evidence.

Here's an example: When Enron's CEO verbally attacked wall street analyst Richard Grubman for questioning Enron's accounting practices, Enron employees thought this was hilarious and adopted the insult as a sort of inside joke. They didn't consider Richard Grubman's position, they just took delight in 'their team' dunking on 'opposing team.'