Beyond the Exponential: Thermodynamic Origins of Rational Delay Discounting

Why do humans and animals consistently choose smaller-sooner rewards over larger-later ones, defying the predictions of classical exponential models? Decades of behavioral research point to hyperbolic and rational discount functions as better descriptors of intertemporal choice, but the reason why these forms emerge has remained elusive. In this paper, we argue that the structure of delay discounting is not merely psychological—but thermodynamic. Drawing on entropy-based formulations of value, we sho...