Monkeys Are People Too

Keith Chen’s research agenda was inspired by something written long ago by Adam Smith, the founder of classical economics: “Nobody ever saw a dog make a fair and deliberate exchange of one bone for another with another dog. Nobody ever saw one animal by its gestures and natural cries signify to another, this is mine, that’s yours; I am willing to give this for that.”

In other words, Smith was certain that humankind alone had a knack for monetary exchange.

But was he right?

In economics, as in life, you’ll never find the answer to a question unless you’re willing to ask it, as silly as it may seem. Chen’s question was simply this: What would happen if I could teach a bunch of monkeys to use money?

Chen’s monkey of choice was the capuchin, a cute, brown New World monkey about the size of a one-year-old child, or at least a scrawny one year-old who has a very long tail. “The capuchin has a small brain,” Chen says, “and it’s pretty much focused on food and sex.” (This, we would argue, doesn’t make the capuchin so different from many people we know, but that’s another story.) “You should really think of a capuchin as a bottomless stomach of want. You can feed them marshmallows all day, they’ll throw up, and then come back for more.”

To an economist, this makes the capuchin an excellent research subject.