To blow hot and cold under stress - neurohormonal moderators of revealed preferences

• Applicant: Professor Dr. Tobias Kalenscher
• Subject Area: Biological Psychology and Cognitive Neuroscience
• Term: from 2021 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 458314306

• Final Report Year: 2025

Final Report Abstract

We investigated the effects of stress and stress-related neuromodulators on economic rationality and social preferences. One major objective was to determine whether stress alters economic preferences to a degree that choices will appear internally inconsistent as a proxy for economic rationality. Consistency was measured using the Critical Cost Efficiency Index (CCEI). Our findings indicated that neither psychosocial stress nor pharmacological manipulation of the stress system with hydrocortisone and yohimbine significantly affected economic rationality or choice consistency. While exploratory results suggested a weak association between chronic stress and lower choice consistency, the overall conclusion was that acute stress does not impair choice consistency. To understand why we failed to show stress, or stress neuromodulator effects on choice consistency, we determined the reliability of the CCEI and related rationality indices. The analysis of multiple datasets involving over 1,600 participants revealed that the most commonly used rationality indices, including the CCEI, exhibit poor test-retest reliability. The variance in rationality indices was essentially non-interpretable. This calls into question their usability as a trait measure in behavioral economics research, which may explain why we failed to find stress effects on rationality. We also examined how stress-related neuromodulators influence social preferences, particularly in intergroup conflict scenarios. A placebo-controlled pharmacological study found that cortisol promoted in-group generosity, reinforcing social bonds, while noradrenaline action increased parochial altruism, leading participants to favor their in-group while harming an out-group. These findings challenge the traditional view that stress promotes either fight-or-flight or tend-and-befriend behaviors, instead suggesting that both responses can occur simultaneously, depending on the context and the particular composition of the neurohormonal stress response. Our findings have implications for understanding the neurobiology of conflict: our results can explain why groups under threat often become more cohesive internally while displaying increased hostility toward outsiders. Overall, the research findings indicate that while stress does not significantly impact economic rationality, measured as choice consistency, it does influence social preferences, particularly in intergroup contexts. Crucially, our findings challenge the reliability of economic rationality metrics, calling into question their usefulness as individual trait measures of rationality. These insights contribute to a deeper understanding of the neurobiological mechanisms underlying prosocial behavior and decision-making under stress.

Publications

• Keeping a cool head at all times. What determines choice consistency?. Center for Open Science.
  Nitsch, Felix Jan & Kalenscher, Tobias
  
• How robust is rational choice?. Center for Open Science.
  Nitsch, Felix Jan & Kalenscher, Tobias
  
• Influence of memory processes on choice-consistency. Royal Society Open Science, 8(10).
  Nitsch, Felix J. & Kalenscher, Tobias
  
• The effects of acute and chronic stress on choice consistency. Psychoneuroendocrinology, 131, 105289.
  Nitsch, Felix J.; Sellitto, Manuela & Kalenscher, Tobias
  
• Trier social stress test and food-choice: Behavioral, self-report & hormonal data. Data in Brief, 37, 107245.
  Nitsch, Felix Jan; Sellitto, Manuela & Kalenscher, Tobias
  
• On the reliability of individual economic rationality measurements. Proceedings of the National Academy of Sciences, 119(31).
  Nitsch, Felix J.; Lüpken, Luca M.; Lüschow, Nils & Kalenscher, Tobias
  
• Do stress hormones influence choice? A systematic review of pharmacological interventions on the HPA axis and/or SAM system. Social Cognitive and Affective Neuroscience, 19(1).
  Sarmiento, Luis Felipe; Ríos-Flórez, Jorge Alexander; Rincón Uribe, Fabio Alexis; Rodrigues Lima, Rafael; Kalenscher, Tobias; Gouveia, Amauri & Nitsch, Felix Jan
  
• Steeper social discounting after human basolateral amygdala damage. Proceedings of the National Academy of Sciences, 122(16).
  Kalenscher, Tobias; Lüpken, Luca M.; Stoop, Ron; Terburg, David & van Honk, Jack