The closing paragraphs kill me.
[quote]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.)
This is a sensitive subject. The capuchin lab at Yale has been built and maintained to make the monkeys as comfortable as possible, and especially to allow them to carry on in a natural state. The introduction of money was tricky enough; it wouldn’t reflect well on anyone involved if the money turned the lab into a brothel. To this end, Chen has taken steps to ensure that future monkey sex at Yale occurs as nature intended it.
But these facts remain: When taught to use money, a group of capuchin monkeys responded quite rationally to simple incentives; responded irrationally to risky gambles; failed to save; stole when they could; used money for food and, on occasion, sex. In other words, they behaved a good bit like the creature that most of Chen’s more traditional colleagues study: Homo sapiens.