Individual differences in the delay-reward heuristic: An exploratory study of socioeconomic status, subjective status, and personal relative deprivation

Recent research has examined the role of inference in intertemporal choice: when a future financial reward is ambiguous, people's inferences about its value depend upon the delay until its delivery, and inferences about ambiguous delays depend upon the size of the stated reward. Here we report an exploratory study of individual differences in this \textit{delay-reward heuristic} by examining whether people's inferences about ambiguous future rewards correlate with objective and subjective indicators of socio-economic status: annual household income, education, self-placement in a national hierarchy of social status (SSS), and self-reported personal relative deprivation (PRD). Participants were presented with a hypothetical choice between receiving £10 now and an ambiguous reward in 1 year's time, and had to infer the missing value. In multiple regression analyses, age and household income emerged as unique predictors that were negatively associated with (log-transformed) estimates, although the effect of income became unreliable when this variable was log-transformed; the effects of SSS and PRD were not reliably different from zero. When participants were subsequently asked to assume that their inferences of the missing value were correct and choose between the immediate and delayed option, larger estimates were positively associated with greater willingness to wait; choices were also predicted by age, income and SSS although the latter two effects were not unambiguously non-zero, and in multiple regression analysis only participants' estimates of the reward emerged as a reliable predictor of preference. Taken together, these results support previous work suggesting that age is a meaningful predictor of inferences about ambiguous rewards and delays, and provide initial evidence that such inferences may also be associated with income.