Does Power Corrupt? An fMRI Study on the Effect of Power and Social Value Orientation on Inequity Aversion

Accumulating evidence corroborates that power asymmetries influence how people respond to violations of the equality norm. We investigate with functional magnetic resonance imaging how preferences for advantageous (receiving more than other) and disadvantageous (receiving less than other) inequality are affected by having social power and whether or not this differs according to an individual's social value orientation. Forty participants were primed with either a leader- or a teammate role (control) before conducting a task in the scanner during which they rated 36 monetary distributions which varied in degree of inequality. Behavioral data indicate that taking on a leader role generally increases aversion to disadvantageous inequality (DA-IE), but that it decreases aversion to larger advantageous inequality, especially for proself individuals. Consistently, the blood oxygen level-dependent (BOLD) data reveal that, as advantageous inequality mounts and the temptation to have more than others increases, leaders show reduced neural activation in regions associated with perspective taking and cognitive control (precuneus and frontal eye field). Proself leaders in particular show reduced activity in the left and right dorsolateral prefrontal cortex, which could be interpreted as a weaker restrain of self-interest when processing advantageous inequality. We found no evidence for an effect of power on processing DA-IE.