Analysis of inequality aversion in mice using stress-induced hyperthermia

Publication date: November 2019Source: Learning and Motivation, Volume 68Author(s): Shigeru WatanabeAbstractHumans have a sense of fairness and consequently have an aversion to inequality condition. Recently, animal researchers have suggested that some non-human animals also exhibit an aversion to inequality. This experiment used stress-induced hyperthermia (SIH) to examine inequality aversion in mice. Aversion was analyzed using inequitable restraint stress in Experiment 1. The mice that were restrained, but had free cage mates (disadvantageous inequality) displayed SIH. In contrast, free mice that had restrained cage mates (advantageous inequality) did not show SIH. Inequitable food delivery was used to induce SIH in Experiment 2. Food deprived mice who were surrounded by cage mates who were consuming food (disadvantageous inequality) displayed SIH. The mice that received food and were surrounded by food-deprived cage mates (advantageous inequality) also showed some increase in body temperature, but the increase was not significantly higher than that in the equality condition (where all mice received food). Pre-feeding of the test mice attenuated SIH in the disadvantageous condition suggesting that satisfied mice do not display disadvantageous inequality aversion. These results showed disadvantageous inequality aversion in mice in both negative (restraint) and positive (food) situations but not advantageous inequality aversion.
Source: Learning and Motivation - Category: Psychiatry & Psychology Source Type: research