In an experiment a group of monkeys are placed in a room with a ladder and on top of the ladder some bananas.
When a monkey tries to climb, all monkeys receive jets of cold water as punishment. Over time none of the monkeys climbs the ladder.
A new monkey is introduced, replacing one of the initial monkeys. When the new one tries to get the bananas, all monkeys in the group fight the daring monkey to prevent the cold water punishment.
The process is repeated: a new monkey is exchanged and all remaining monkeys teach the lesson (the hard way) to the new monkey; the other new monkey -that has never recevied the shower of cold water- also participates in teaching the lesson.
All monkeys are exchanged, and none of the original bunch remains. But the monkeys will not allow any newcomer to try reaching the bananas, despite they have not suffered the cold water punishment themselves.
Free interpretation of the investigations by Gordon R. Stephenson, Stephenson, G. R. (1967), Cultural Acquisition of a Specific Learned Response Among Rhesus Monkeys – In: Starek, D., Schneider, R., and Kuhn, H. J. (eds.), Progress in Primatology, Stuttgart: Fischer, pp. 279-288.
The tale of the monkeys and the bananas is widely used to illustrate how uses get into our daily life, even though we have not an idea of the reasons that lead to that behavour. We simply follow the herd.
I first read bout this tale in the 2000s, and around 2018 or 2019 found a reference to the original Stephenson's studio in the book Desayuno con partículas, by Sonia Fernández-Vidal.
But the truth is that neither the original investigation nor its results are those in the tale. This page elaborates on these significant differences.
All and all, despite being false (as many apocryphal quote), it may trigger some critical thinking on why we keep on doing things in the way we do. This can be material for a self-help chat, but definitely not scientific in any way.
With this piece of disclaimer, use the monkeys and bananas story at your own criteria; and, at least, mention that it is not based on an actual scientific study.