If you haven't heard of it here's the story, well, one version of it.
The concept is collective conscience or intelligence.
A group of monkeys on isolated islands are compared and taught new tricks.
Monkeys are taught to wash potatoes prior to eating on one island but not the other, when a lot of monkeys readily accept this new method the observers notice on the other island ... (out of view) that those monkeys just start washing their potatoes too. They figured when enough monkeys (ie the 100th) takes up the task then it sort of becomes a collective conscience ESP thing that other monkeys start to do.
So, is this all BS? 
And also, this is used to try and draw some understanding to the pyramids being built in Egypt and South America.