Those familiar words of indignation span all ages, from the child who covets a playmate’s toy to the adult who learns a co-worker earns more money doing the same job. Humans have a keen sense of ...

In a TED talk, primatologist Franz de Waal jokes that a philosopher wrote to him that it isn’t possible for monkeys to have a sense of fairness since fairness wasn’t invented until the French ...

A sense of fairness has long been considered purely human -- but animals also react with frustration when they are treated unequally by a person. In a study with long-tailed macaques (Macaca ...