Animal Fairness: Myth or Reality?

A study from Germany suggests that long-tailed macaques were more likely to reject an inferior reward from a human than from an automatic feeding machine, meaning they can distinguish between the two and react to the difference. The research looked at four different experimental conditions and found that the subject monkeys more often refused the low-value food from the humans but accepted the same low-value food from the machine. The study suggests that “social disappointment” with humans may play a role in the monkeys' behavior.