It’s a question that has puzzled thinkers for centuries: Are we humans alone in our pursuit of fairness and the frustration we feel when others get what we want? In recent years, evolutionary ...

Experiments show that some monkeys reject rewards when they perceive unfair treatment, demonstrating a behavior known as inequity aversion. In controlled studies, individuals refused food when another ...

A sense of fairness may be ingrained in all primates. It is an essential ingredient in functional societies because it makes social relationships predictable. Predictability matters because animals ...