In this project the Principal Investigators will examine metabolic mechanisms underlying intertemporal choice, delay (future) discounting, and impulsiveness within an interdisciplinary framework of evolutionary psychology and life-history theory. People discount the future or delayed rewards when they value present goods over future goods and when they prefer a smaller and sooner (SS) reward to a larger and later (LL) reward in making intertemporal choices.
Recent research has revealed a novel link between fluctuating blood glucose levels and delay discounting. The study showed that a sugar drink reduced delay discounting, making the LL options more attractive whereas a diet drink increased delay discounting, making the SS options more preferable. This observation is consistent with the hypothesis that glucose is a cognitive resource and with the hypothesis that blood glucose level is a signal of energy budget status. The funded research will examine how bodily changes in glucose levels, along with variations in steroid hormones and seasonal changes in metabolic rates, affect delay discounting and impulsiveness of decision makers to determine which of these hypotheses better accounts for the effects of blood glucose on delay discounting. Additional experiments will examine tradeoffs between present-orientation for survival and future-orientation for mating and reproduction as a function of metabolic conditions.
This project has broad applied implications. The ability to delay gratification has been shown to lead to less psychopathology, better grades, less substance use, and more overall success in life. Thus, instilling greater delay of gratification would lead to more productive and healthier lives. By identifying metabolic conditions that increase or decrease delay discounting and impulsiveness, we would be able to help design better interventions for addictive and obsessive-compulsive behaviors. The knowledge gained from the proposed studies should provide guidance for promoting positive health behavior.
