A group of scientists placed five monkeys in a cage, and in the middle, a ladder with bananas on top.
Every time a monkey went up the ladder, the scientists soaked the rest of the monkeys with cold water.
After a while, every time a monkey would start up the ladder, the others would pull it down and beat it up.
After a time, no monkey would dare try climbing the ladder, no matter how great the temptation.
The scientists then decided to replace one of the monkeys. The first thing this new monkey did was start to climb the ladder. Immediately, the others pulled him down and beat him up.
After several beatings, the new monkey learned never to go up the ladder, even though there was no evident reason not to, aside from the beatings.
The second monkey was substituted and the same occurred. The first monkey participated in the beating of the second monkey. A third monkey was changed and the same was repeated. The fourth monkey was changed, resulting in the same, before the fifth was finally replaced as well.
What was left was a group of five monkeys that – without ever having received a cold shower – continued to beat up any monkey who attempted to climb the ladder.
If it was possible to ask the monkeys why they beat up on all those who attempted to climb the ladder, their most likely answer would be “I don’t know. It’s just how things are done around here.”
Does that sound at all familiar?
Source: This story, a modern day fable, was inspired in part by the experiments of G.R. Stephenson, found in “Cultural acquisition of a specific learned response among rhesus monkeys“ as well as certain experiments with chimpanzees conducted by Wolfgang Kohler in the 1920s. Over the years, it was pieced together to form the urban legend as it now stands. If you enjoyed this post, you may appreciate the similar Hundredth Monkey Effect.