I would suggest you read Chapter 4 of "The Psychology of Persuasion" dealing with social proof. To summarize what it describes, in times of uncertainty we look to other people to see how to act. However, in some cases no one knows how to act so we are all looking to each other for clues. Since we prefer to appear unflustered among others, we will all see each other reacting as if there is no emergency and therefore act that way ourselves.
The book also describes those factors that increase the likelihood of this happening. Large, distracting places where it is difficult to be certain of the nature of the encounter, more people in the area, and low levels of acquaintanceship. All of these factors are present in urban environments.
An excellent book I would recommend reading to anyone. |