Capuchin Monkeys Steal Coins And Exchange Them For Sex When Taught The Use of Currency

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Updated on 4 Sep, 2017 at 5:12 pm

The legendary economist Adam Smith, predicted in one of his theories, that the phenomenon of monetary exchange will be restricted to human beings only. In other words, no other species on earth will trade money for anything in return.

However, what has happened during a research at Yale-New Haven Hospital laboratory is completely different.

When Capuchin monkeys were taught how to use money, they began trading it for sex. The researchers, however, did not play any role in teaching them to carry out this particular exchange. They, in fact, directed them to transact coins for Jell-O or grapes.

Capuchin monkeys, who always have either food or sex on their mind, are brown in color and of a size comparable to that of a human baby. Two researchers, Keith Chen, a Yale economist and Laurie Santos, a psychologist, played on the natural desires of the animal to find out the result of introducing currency into their community.

They gave “kind of like Chinese money”, a silver disc, one inch in diameter and a whole in the center, to a monkey to see what he did with it. For several months, they were trained to value these tokens as a means of exchange for a treat.



Some of them were then presented with 12 tokens on a tray to see how many of these coins they were ready to surrender for grapes vs Jell-O cubes. The repercussions of this were a bit strange as these Capuchin monkeys started tossing these coins in their neighboring cell, where all the monkeys would rush to grab as many of them as they could. But not all of them were fortunate enough to be able to collect some coins.

The monkeys that could not grab any coins found out an ingenious way of earning them – trading sex for money! The monkey who paid for sex instantly transacted the coins he earned to buy grapes.

The turn that the experiment took wasn’t the same as researchers had expected, or intended, it to take. Therefore, steps were taken to make sure that in future, monkey sex in Yale occurs as a natural process.

So the facts and findings of the research say – When taught the use of currency, Capuchin monkeys stole money when they could and exchanged it for food, and on occasion, for sex.