Though sometimes referenced as such, the monkey ladder — or monkey ladder experiment / monkey psychology experiment — was never a specific experiment per se. It’s more of an urban legend that has become somewhat of a trope, but with good reason. Read on.
The Monkey Ladder
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 certain amount of this, each time a monkey would to start up the ladder, the others would pull it down and beat it up; this too went on for a while, but eventually 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, of course, 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?
The most damaging phrase in the language is: 'It’s always been done that way.' ~ Grace Hopper Click To Tweet
This tale, an urban legend pieced together across decades to become the amusing and telling anecdote you find here, has its origins in certain experiments conducted in the early 1900’s by Wolfgang Köhler, a German psychologist who was pivotal in the development of Gestalt theory.