Does temporal discounting explain unhealthy behavior? A systematic review and reinforcement learning perspective.

Area of Science:

• Behavioral Economics
• Neuroscience
• Health Psychology

Background:

• Unhealthy choices are common despite awareness of risks.
• Temporal discounting, devaluing future rewards, is a proposed mechanism.
• Hyperbolic discounting specifically may explain intention-behavior gaps.

Purpose of the Study:

• To review evidence linking temporal discount rates to unhealthy behaviors.
• To assess if hyperbolic discounting explains intention-incongruent unhealthy actions.
• To propose a framework for understanding health decision-making.

Main Methods:

• Systematic literature review of studies on discounting and health behaviors.
• Analysis of intention-incongruent actions in relation to hyperbolic discounting.
• Proposal of a dual-system reinforcement learning framework (model-based vs. model-free).

Main Results:

• High discount rates for rewards (money, food, drugs) correlate with unhealthy behaviors and health status markers.
• Intention-incongruent unhealthy actions are often triggered by environmental cues or motivational shifts, not solely by hyperbolic discounting.
• Unhealthy behaviors can become habitual (model-free) through repetition, persisting even with changing goals.

Conclusions:

• Temporal discounting is a promising predictor of unhealthy behaviors.
• Hyperbolic discounting alone does not fully explain intention-incongruent unhealthy actions.
• A dual-system model (goal-directed and habitual) offers a framework for understanding state-based effects in health decisions, potentially identifying distinct phenotypes.