It's about time: Specific and unspecific effects of episodic future thinking on farsighted decisions

Humans tend to discount the value of delayed rewards. As a consequence, they forego larger long-term benefits (e.g., €29 in 91 days) in favor of smaller short-term gains (e.g., €20 now). Episodic future thinking (EFT) attenuates such delay discounting. That is, people are more likely to choose a larger but delayed reward after imagining an episode at the future time point (e.g., a café visit in 91 days). We here elucidate the underlying mechanism by examining the temporal specificity of this effect. Does EFT foster farsighted decisions in general by shifting the mental focus towards the future, or does it specifically influence decisions in favor of the imagined time point? In two experiments (n = 84 total) we systematically varied the concordance between the imagined time point and the delay at which the larger reward could be received. When these time points matched, we replicated the beneficial effect of EFT (Experiments 1 and 2). Critically, when the imagined time point matched the sooner of two delayed choice options, the effect was reversed: Choices became more short-term (Experiment 1). When the imagined delay was double the delay of the larger option, the effect was not significant and numerically lower than when the delays matched (Experiment 2). Notably, more vivid imaginations were associated with more farsighted choices at longer delays, irrespective of whether the imagined time point matched the delayed choice. Together, the data demonstrate that both temporally specific and unspecific mechanisms contribute to the impact of EFT on delay discounting.