Willingness to wait covaries with endogenous variation in cortisol

Evgeniya Lukinova^1*Jeffrey C Erlich^2*

• ¹University of Nottingham, Nottingham, United Kingdom
• ²University College London, London, England, United Kingdom

Stress is a normal part of our everyday lives alerting us to changes in our environment and working as an early warning system. However, when stress is prolonged, it can become harmful. The deleterious effects of stress on brain function are well established: chronic stress significantly impairs cognitive function reducing our ability to solve problems and to regulate behavior and, therefore, may lead to more challenges that can further exacerbate stress. An important class of decisions that may be made under stress includes those between rewards delivered immediately vs. those delivered in the future. Not considering or devaluing future outcomes (delay discounting) can result in adverse outcomes such as not buying health insurance, gambling or drug use. To date, however, little is known about how chronic stress influences economic decisions that differ in the time of outcome delivery. A handful of studies suggest that increased stress may lead to more impulsive choices in subjects of average socioeconomic status and stress levels. Here, we addressed this gap by using a multi-session design to determine whether chronic stress measures (via questionnaires, saliva and hair samples) are associated with the economic choices under different time scales within subject (N = 34). We found that the degree to which people think it is worth waiting, i.e. individual's discount factor, over seconds, but not over days, varied reliably with endogenous stress. These results are imperative to understanding the impact of stress in a variety of contexts. For instance, fluctuations in individual stress responses to environment may help explain variations in consumer behaviors, such as impulse purchases, even among healthy adults.