Monkeys reject unequal pay
SARAH F. BROSNAN & FRANS B. M. DE WAAL
Nature 425, 297–299 (2003)

"A cucumber should be well sliced, and dressed with pepper and vinegar, and then thrown out, as good for nothing". Dr Samuel Johnson's views (quoted in Boswell's Tour to the Hebrides) are close to those of brown capuchin monkeys. A monkey willing to perform a task for a cucumber may refuse to do so if its partner is given a tasty grape. "It's not fair", the complaint of children the world over, is the message. In balking at this unequal pay, the monkey is surely being irrational, rejecting food that is on offer. But the negative emotion of "unfairness" and the refusal to accept inequitable situations has been a positive influence in the long-term in the development of human society, and the same evolutionary pressures seem to have prevailed in other primates as well.

I loved reading this article. In humans that is well known from laboratory studies: Participants often rather would take less money if they know another participant gets the same amount than get more but see the other participant walk away with much more money for the same work or the same money for less work.

This reminds me of what I consider one of the more stupid stories in the Bible, the workers in the vineyard (my translation may be far off, but it is in Mt 20). They complain that they get the same pay for a full day's work as those who only did work for an hour. The employer then says they should not complain for they did get what he had promised. The crooked logic in that story never takes into account how real humans (and monkeys) are.

Wolfgang