… Just like humans asked to choose between the government plans A and B, our monkeys bought more food from Salesman A than from Salesman B. Like people, they preferred to play it safe when dealing with bonuses.
We then introduced monkeys to two new salesmen, C and D, whose payoffs felt like losses. Salesman C always gave a small but consistent loss — he showed the monkeys three apple pieces but gave them only two in return for the token. Salesman D was riskier. He began by showing the monkeys three pieces and sometimes gave them all three but other times gave them only one. As predicted, our monkeys took greater risks when their token payments felt like losses; that is, they consistently preferred to trade with risky Salesman D over reliable (but shortchanging) Salesman C.