in the costa book, she describes an experiment scientists did with monkeys. they trained them to use money to buy food with, various food was different prices and the monkeys would actually work out how to buy what they liked, how to get change, how to borrow money, horde it, lend it and the females started to offer sex for money.
eventually they shut the experiment down. what ya think about that?
it's kinda evil really. 
costa, goes on to explain in her extreme economic super meme chapter that debt is what stops innovation as well, and currently the whole world is in debt. she speculates that's where the monkey's were heading with the money experiment.