A scientist puts 5 monkeys in a large cage. At the top of the cage is a bunch of bananas.Underneath the bananas is a ladder.
One monkey begins to climb the ladder.The scientist sprays him, and the other 4 with ice-cold water jets.The monkey on the ladder jumps off, and all 5 sit for a time on the floor, shivering and bewildered.Soon, another monkey begins to climb the ladder.Again, they are all sprayed with ice-cold water.When a third monkey tries to climb the ladder, the other monkeys grab him, pull him off the ladder and beat him.
Now one monkey is removed and a new monkey is introduced to the cage. Spotting the bananas, he begins to climb the ladder.The other monkeys pull him off and beat him.
The second one of the original monkeys is replaced with a new monkey. Again, the new monkey begins to climb the ladder and, again, all the other monkeys pull him off and beat him.
At the end of the experiment, 5 monkeys who have never been iced down – attack and beat any new monkey who makes a move on the bananas.
“Cultural acquisition of a specific learned response among rhesusmonkeys” by Stephenson et al