What does fear do to our vision? [Digest.BPS.org.uk]
Consider the following scenario. A policeman is on patrol, maybe he's quite new to working in the field. He sees a suspicious young man and decides to follow him. He turns the corner and sees that the man has drawn a gun from his pocket. In a snap second – almost too fast to think twice – he takes out his own gun and shoots the man dead. Only the man didn't have a gun at all, it was a mobile phone. Sadly, it's a familiar story. An incident exactly like it occurred only last week ...