A Computational Model of Non-optimal Suspiciousness in the Minnesota Trust Game

This study modelled spite sensitivity, the worry that others are willing to incur a loss hurt you, which is thought undergird suspiciousness and persecutory ideation. Two samples performed parametric, non-iterative trust game known as Minnesota Trust Game (MTG). The MTG distinguishes suspicious decision-making from otherwise rational mistrust by incentivizing player in certain situations but not others. In Sample 1, 243 undergraduates who completed showed less amount of money they could lose increased. However, only for choices where partners had financial disincentive betray was variation willingness associated with beliefs. We modified Fehr-Schmidt (1999) inequity aversion model, compares unequal outcomes social tasks, include possibility spite sensitivity. An anticipated partner’s dislike advantageous (i.e., guilt) parameter included negative values, guilt indicating spite. hypothesized would be strongly related Our modification model improved estimation behavior. Furthermore, spite-guilt highly correlated beliefs persecution. replicated our findings second sample. weakly self-reported measure ideation 2. “Suspiciousness” condition, unique MTG, can modeled isolate sensitivity, suggesting differentiation or risk aversion. offers promise future studies quantify clinical populations.