Decisions between differently timed outcomes are a well-studied topic in as diverse academic disciplines as economics, psychology, and behavioral ecology. Humans and other animals have been shown to make these intertemporal choices by hyperbolically devaluing rewards as a function of their delays (‘delay discounting’), thus often deemed to behave myopically. In behavioral ecology, however, intertemporal choices are assumed to meet optimization principles, that is, the maximization of energy or reward rate. Thus far it is unclear how different approaches assuming these two currencies, reward devaluation and reward rate maximization, could be reconciled. Here we investigated the degree at which humans (N = 81) discount reward value and maximize reward rate when making intertemporal decisions. We found that both hyperbolic discounting and rate maximization well approximated the choices made in a range of different intertemporal choice design conditions. Notably, rate maximization rules provided even better fits to the choice data than hyperbolic discounting models in all conditions. Interestingly, in contrast to previous findings, rate maximization was universally observed in all choice frames, and not confined to foraging settings. Moreover, rate maximization correlated with the degree of hyperbolic discounting in all conditions. This finding is in line with the possibility that evolution has favored hyperbolic discounting because it subserves reward rate maximization by allowing for flexible adjustment of preference for smaller, sooner or larger, later rewards. Thus, rate maximization may be a universal principle that has shaped intertemporal decision making in general and across a wide range of choice problems.

Demographic and discounting data of participantsIn the xlsx file the demographic data (i.e., gender and age) of our 81 participants are included. Moreover, we included the larger-later option choice proportion for each of the 6 blocks of both tasks (i.e., self-control design and patch design) along with the respective earnings. Then, we list the computed hyperbolic log-k values for the two tasks (as well as for the two tasks collapsed) and for the Kirby task. Then we included the computed Long Term maximization Rate (LTR) for the two tasks (considering both all choices and only the last 5) and the Akaike Information Criterion for both the LTR and the hyperbolic models for both task designs.Finally, we included the performance at the time production task at each of the four delay conditions and the scores at the Barrat Impulsiveness Scale subscales and at the Quick Delay Questionnaire subscales.Seinstra_data.xlsx