Freakonomics in the Times Magazine: Monkey Business

Dubner and Levitt are writing a new monthly column in the New York Times Magazine. The column, like their book, is called Freakonomics. The first installment, “Monkey Business,” concerns a young Yale economist who is teaching capuchin monkeys to use money. Click here to read the full article. Read below for bonus matter.

Keith Chen is a 29-year-old Yale economist who is teaching capuchin monkeys to use money. Why? Well, to see what they spend it on, and how their spending might relate to human spending.

Chen and his colleagues have run a series of nifty experiments, described thusly by Chen: “A capuchin monkey must decide how to spend his budget of twelve coins (located on the yellow and white striped tray in the front of the trading room.) Two human research assistants are present (one wearing blue and one wearing red), and both hold a piece of food in an orange dish for the monkey to see. The red research assistant ‘sells’ grapes and the blue research assistant ‘sells’ Jell-o cubes, with each piece of food costing a coin from the monkey’s budget. The capuchin must make a decision analogous to a grocery-store shopper’s: how much of their budget to spend of grapes and how much to spend on Jell-o.”

Before he came to Yale, Chen helped run some monkey experiments at Harvard on cotton-top tamarins: “Two unrelated tamarin monkeys sit adjoining each other. Every fifteen seconds, a human research assistant brings a tray loaded with a marshmallow that is just out of reach of one of the monkeys. The only way that monkey can eat the treat is if his partner pulls a red handle that will put the marshmallow within reach. But pulling the handle doesn’t bring any reward for the puller: pulling the handle only pays if the monkey who receives the marshmallow reciprocates by pulling in the future. Like many human situations, the monkeys must work together to obtain food and build trust while punishing failures to cooperate.”

For more information about Keith Chen, including his academic papers on free-spending monkeys and other economic phenomena, click here.