Paradox of Time: How Constraints and Abundance Shape Decision-Making and Cognition

Background Intertemporal decision-making involves balancing immediate benefits against future outcomes, affecting crucial domains such as financial planning and health behaviors. Time pressure substantially shapes these decisions: constrained time typically encourages intuitive reasoning and decision biases, whereas sufficient time facilitates more deliberative processing. Nevertheless, existing research has largely overlooked conditions involving delayed responses, limiting a comprehensive understanding of how varying temporal constraints influence intertemporal choice. Methods Sixty-five participants (30 males; mean age 22.5 years) completed intertemporal choice tasks under three conditions: time-constrained (decision within 3 seconds), baseline (unlimited decision time), and delayed response (decision after 5 seconds). Behavioral measures, including reaction times and choices (short-term vs. long-term options), were recorded. Additionally, eye-tracking data—Outcome Gaze Proportion (OGP) and pupil diameter (PD)—were collected to assess attention allocation and cognitive-emotional load during decision-making. Results Reaction times differed significantly across conditions, with the shortest times observed in the time-constrained condition and the longest in the delayed response condition. Participants showed an increased preference for short-term rewards as decision time increased, suggesting a paradoxical rise in impatience under extended deliberation. Eye-tracking data indicated that Outcome Gaze Proportion (OGP) increased with longer decision windows, reflecting more attention to outcome attributes, whereas pupil diameter (PD) was largest under time pressure, signaling heightened cognitive and emotional load. Mediation analyses confirmed that both OGP and PD significantly mediated the relationship between time condition and choice behavior, suggesting that attention allocation and physiological arousal jointly shape intertemporal preferences. Conclusion Time shapes not only the speed but also the quality of intertemporal choices by modulating attention and emotional arousal. Our findings reveal that both time pressure and delay systematically influence decision preferences, highlighting the need to consider temporal context in models of self-control and decision optimization.