Animals, self-interest, rewards, and fairness
Posted by c. wagner on November 12, 2009
Interesting research about how animals seem to have a sense of fair play.
We would offer a pebble to one of the pair and then hold out a hand so that the monkey could give it back in exchange for a cucumber slice. Alternating between them, both monkeys would happily barter 25 times in a row. The atmosphere turned sour, however, as soon as we introduced inequity. One monkey would still receive cucumber, while its partner now enjoyed grapes, a favourite food with monkeys. While that monkey had no problem, the one still working for cucumber would lose interest. Worse, seeing its partner with juicy grapes, this monkey would get agitated, hurl the pebbles out of the test chamber, sometimes even those measly cucumber slices. A food normally devoured with gusto had become distasteful.
Discarding perfectly fine food simply because someone else is getting something better resembles the way we reject an unfair share of money or grumble about an agreed-upon rate of pay. Where do these reactions come from? They probably evolved in the service of cooperation. Caring about what others get may seem petty and irrational, but in the long run it keeps one from being taken advantage of.
And if the system of rewards gets far enough out of balance, the animals getting the poorer rewards may make life tough for the critter with the better rewards. While acting in self-interest is the default, the tendency can be overridden in cases where there might be repercussions from greed. In other words, spreading the wealth, at least a little bit, might be advantageous and part of the make-up of social animals. The concept is at least interesting enough for further research.