8 Science Facts They Probably Didn't Teach You In School

8. Monkeys Can Be Taught To Use Money... But Use It For Gambling And Prostitutes

The more we learn about our primate cousins, the more we discover how similar we are. Unfortunately, that also includes some of humanity's more unsavoury aspects.

Amazingly, Capuchin monkeys can actually be taught how to use money. In 2005 Keith Chen and his colleague Laurie Santos, trained a troop of capuchin monkeys to use a made-up currency of little silver discs with a hole in the middle. The monkeys would trade the disks with the researchers for grapes and little cubes of jelly. They even managed to grasp the concepts of inflation and market value.

They also, however, grasped the concept of gambling, making the same irrational decisions and showing the same signs of superstition as human gamblers. What's more, they quickly figured out that the money could not only be used to get jelly and grapes, but also sex.

One day, one of the researchers spotted a transaction being made between two monkeys out of the corner of his eye. He saw a male monkey exchange some silver tokens for sex with female monkey. In different experiments, male rhesus macaque monkeys have been observed "paying" (using juice as currency) to see female rhesus macaques’ bottoms. It's kind of like the simian version of tipping a stripper.