A behavioral measure for spite.

Spite occurs when someone harms another individual at a personal cost to themselves. Spite is studied by evolutionary biologists and personality psychologists, but little behavioral spite research exists. A social discounting task was modified to determine whether repeated choices to spite a disliked person would decrease with social distance and/or increase as loss amount for the other disliked person increased. In Experiment 1, more than 50% of participants made at least one spiteful choice, resulting in less hypothetical rewards for themselves. Spite rates generally decreased hyperbolically as social distance increased but did not increase as loss amount for the other person increased. Experiment 2 enrolled older participants and showed that participants increased spiteful choices as the loss amount for the other person increased, although not for pairwise comparisons or in a hyperbolic manner. However, spiteful choices were significantly related to self-reported Spitefulness Scale and Machiavellianism scores, showing concurrent validity. Perceived social distance ratings for both liked and disliked individuals showed significant asymmetry, with disliked individuals perceived at larger social distances. Cumulatively, these results demonstrate that spite can be measured using a social discounting task and that generosity and spite may be governed by different processes. This opens new research pathways to quantify causal variables for spiteful behavior.