February 27, 2014
As the well-known primatologist Frans de Waal can be heard explaining in that clip — or with a bit more detail in the one that follows this paragraph — capuchin monkeys “get” unfairness.
In the filmed experiment, one of the monkeys is originally quite satisfied with a cucumber reward for carrying out a task.
But the animal quickly becomes piqued when a second monkey is given a vastly preferable grape reward for carrying out the exact same task.
the video is a selection from:
Moral Behavior in Animal
TED, Nov 2011
Frans de Waal