In one experiment, it was just a matter of giving capuchin monkeys a bunch of silver discs, then demonstrating that they would get a treat when they turned one disc in to the researchers.

有人做过这样的实验，他们给僧帽猴一些银币，并向他们演示如果他们将一块银币交给工作人员，他们将饱餐一顿。