Finally, definitive proof of evolution

I think we all have a tendency towards anthropomorphism, especially when it comes to primates. But who knew it extended to monkeys and money?

A researcher taught capuchin monkeys how to use tokens (money) in exchange for food. Once the monkeys realized that the tokens had value, variations were introduced into the experiment. The researchers allowed the monkeys to decide their favourite food (grapes versus Jello) and the monkeys established how much they were willing to pay for the food. And then the price of the food changed.

If, for instance, the price of Jell-O fell (two cubes instead of one per token), would the capuchin buy more Jell-O and fewer grapes? The capuchins responded rationally to tests like this … when the price of something falls, people tend to buy more of it.

The researchers then introduced gambling. The monkeys were given two gambles involving coin-tossing. In the first gamble, the monkeys bought a grape with their money, but if they won the coin toss they won a second grape. If they lost the coin toss they still kept their original grape. No matter what, they still ended up with at least one grape. The second gamble was the opposite – start off with two grapes and the winner kept both grapes but the loser gives up one grape. The second gamble is more high risk than the first.

How did the capuchins react? They far preferred to take a gamble on the potential gain than the potential loss…in similar experiments, it turns out that humans tend to make the same type of irrational decision at a nearly identical rate…The data generated by the capuchin monkeys, Chen says, ''make them statistically indistinguishable from most stock-market investors.''

Then things started to get interesting. The monkeys began stealing money.

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

It went from interesting to fascinating. The researchers observed a monkey giving money to another in exchange for sex. The monkey who was paid for the sex immediately used her ill-gotten wealth to purchase food.

So the following observations were made in regards to monkeys and money:

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.

It’s getting harder and harder to tell the difference between us and them.