Prostitution in monkeys and penguins (w. petition for Turkey at end)

Are we humans the only species who understand and utilize the dismal science? Can other animals grasp the concept of currencies? Can they trade?

Adam Smith did not think so. He argued in The Wealth of Nations that “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 yours; I am willing to give this for that.”

Driven by their academic curiosity, and also perhaps by their desire to create an army of cheap bankers, researchers at my alma mater Yale launched a study to teach monkeys the concept of money. Through months of repetition, the monkeys were taught to exchange small silver discs for food.

Researchers eventually managed to teach the monkeys that different food items had different costs and allotted each monkey 12 discs to see what they would do. Monkeys turned out to be a lot like humans in the sense that they were miserable savers: Most of them spent all of their tokens at once.

The first-ever monkey bank robbery occurred when, one impulsive primate, presumably driven to crime by his newly-found poverty,  leapt from his cage and seized a tray full of discs before hurrying back to safety.

Supply shocks were simulated by raising and lowering food prices: Researchers presented the monkeys with two equally desirable options, and then slashed the price on one. Monkeys always flocked to the cheaper item, although they did not seem to take any factor other than the price, such as nutritional value and taste, into consideration.

Monkeys were also taught to gamble in games where they had the opportunity to win additional food or lose it all. They showed a natural aversion to risk, a trait researchers now believe to be more innate than learned.

But most interestingly, researchers also observed one of the males making a “dubious” exchange with a female, a barter of “money for pleasure”. As soon as the trade was done, the female ran off  to buy herself some food. The value of the disc was understood by both parties. This first observed instance of animal prostitution in captivity offers an interesting insight into monkey morality.

This experiment is quite well-known among economists, and I always wondered if it would hold hold true in nature. I found the answer thanks to a documentary on Adélie penguins that was airing on Turkish news channel CNNTurk at the height of the Gezi protests this past weekend.

Female Adélie penguins swap sexual favors for pebbles, which they use to make their nests. There was a devastating stone shortage in 1998, and desperate for rocks, breeding females went searching for single males with hefty stone collections. They then traded sex for the building materials. Both parties appeared to have understand the value gained in the exchange.

The world of animals is amazing, even for an economist. I am therefore truly grateful to CNNTurk. And since such a documentary has nothing to do with news, I am suggesting they drop the CNN name. I’d appreciate if you could take a couple of minutes to sign a petition to that purpose.