Psychology 101

If you start with a cage containing five monkeys and hang a banana on a string from the top of the cage, then place a set of stairs under the banana, soon a monkey will go to the stairs and climb towards the banana. When he touches the stairs, you spray all the other monkeys with cold water. After a while another monkey attempts to climb up to the banana and all the other monkeys are sprayed with cold water. Before long, whenever a monkey tries to climb the stairs, the other monkeys will stop him.

Now, put the cold water away.

Remove a monkey from the cage and replace it with a new monkey. The new monkey sees the banana and attempts to climb the stairs. To his shock, the other monkeys beat the crap out of him. After another attempt and attack, he knows that if he tries to climb the stairs he will be
assaulted.

Next, remove another of the original five monkeys, replacing it with a new monkey. The newcomer starts up the stairs and is attacked. The previous newcomer takes part in the punishment... with enthusiasm.

Then, replace a third original monkey with a new one, followed by a fourth, then the fifth. Every time the newest monkey takes to the stairs he is attacked. Most of the monkeys that are beating him up have no idea why they were not permitted to climb the stairs. Neither do they know why they are beating up the newest monkey.

Finally, having replaced all of the original monkeys, none of the remaining monkeys have ever been sprayed with cold water. Nevertheless, none of them will try to climb the stairway for the banana.

"Why?" you ask...? Because in their minds that is the way it has always been.