Nicholas Kristof’s column in this weekend’s New York Times reflects on a now legendary study demonstrating that Capuchin monkeys show a sense of fariness. Pairs of female monkeys (females are believed to most closely monitor equity among their peers) were placed side by side and trained to pass a small granite rock to their human handler in exchange for a reward. In some cases, both monkeys received the same reward (a cucumber slice). However, other times, one of the two received a better reward (a grape, a more desirable food) for the same amount of work or, in some cases, for performing no work at all. The response to the unequal treatment was astonishing: Capuchins who witnessed unfair treatment and failed to benefit from it often refused to conduct future exchanges with human researchers, would not eat the cucumbers they received for their labors, and in some cases, hurled food rewards at human researchers.
Kristof suggests that there is a lesson for everyone here, echoed not only by large bodies of academic research but also real-world scenarios as diverse as baseball team performance and customer unhappiness on airplanes. That is, inequality in America has never been more staggering, is fraying the fabric of American society and today constitutes a public health crisis.