[polly]

The reason people who have been attacked or hurt in anyway do sterotype and dislike/hate entrie subgroups is very primitive. It is a defence mechanism the only way humans know to protect themselves in the future.
Example: when a child burns his hand in the fire he learns not to put his hand in the fire again
When same child is attacked by a gang of kids from Church he learns not to go near kids from Church,for kids from Church please insert any sub group: white, black, Scottish Welsh, etc etc