09 June 2005

The third oldest monkey profession


The oldest? Gambler. Second oldest? Thief.

Amazing But True: Researchers at Yale have been teaching monkeys to use money, looking to see if a) it's possible, and b) how they act with money. The first surprise was that the monkeys did learn to use tokens as a medium of exchange, and were even able to make rational choices that changed as the prices of things changed.

They also learned to gamble. Interestingly, they exhibited the same loss-aversion that humans do.

And, then, well:
Then there is the stealing. Santos has observed that the monkeys never deliberately save any money, but they do sometimes purloin a token or two during an experiment. All seven monkeys live in a communal main chamber of about 750 cubic feet. For experiments, one capuchin at a time is let into a smaller testing chamber next door. Once, a capuchin in the testing chamber picked up an entire tray of tokens, flung them into the main chamber and then scurried in after them -- a combination jailbreak and bank heist -- which led to a chaotic scene in which the human researchers had to rush into the main chamber and offer food bribes for the tokens, a reinforcement that in effect encouraged more stealing.

Something else happened during that chaotic scene, something that convinced Chen of the monkeys' true grasp of money. Perhaps the most distinguishing characteristic of money, after all, is its fungibility, the fact that it can be used to buy not just food but anything. During the chaos in the monkey cage, Chen saw something out of the corner of his eye that he would later try to play down but in his heart of hearts he knew to be true. What he witnessed was probably the first observed exchange of money for sex in the history of monkeykind. (Further proof that the monkeys truly understood money: the monkey who was paid for sex immediately traded the token in for a grape.)
I would bet large sums that the researchers did not list, under experimental risks, the possibility that they would be training monkeys to be prostitutes.