The catch is, if they both choose to steal, they both walk away with nothing.
Players are given 30 seconds to discuss their intentions before making a final decision. Naturally, in most cases, the objective is to convince the other contestant that you are keen to split, and then turn around and pick Steal. It's quite a horrible sight to behold.
However, on a recent episode, one brilliant, altruistic contestant used game theory to persuade the other guy to split the money — by convincing him he was going to steal.