Acute stress may slow down the spread of fears

"The global coronavirus crisis, and the pandemic of misinformation that has spread in its wake, underscores the importance of understanding how people process and share information about health risks under stressful times," says Professor Wolfgang Gaissmaier, Professor in Social Psychology at the University of Konstanz, and senior author on the study. "Our results uncovered a complex web in which various strands of endocrine stress, subjective stress, risk perception, and the sharing of information are interwoven."

The study, which appears in the journal Scientific Reports, brings together psychologists from the DFG Cluster of Excellence "Centre for the Advanced Study of Collective Behaviour" at the University of Konstanz: Gaissmaier, an expert in risk dynamics, and Professor Jens Pruessner, who studies the effects of stress on the brain. The study also includes Nathalie Popovic, first author on the study and a former graduate student at the University of Konstanz, Ulrike Bentele, also a Konstanz graduate student, and Mehdi Moussaïd from the Max Planck Institute for Human Development in Berlin.

In our hyper-connected world, information flows rapidly from person to person. The COVID-19 pandemic has demonstrated how risk information -- such as about dangers to our health -- can spread through social networks and influence people's perception of the threat, with severe repercussions on public health efforts. However, whether or not stress influences this has never been studied.

"Since we are often under acute stress even in normal times and particularly so during the current health pandemic, it seems highly relevant not only to understand how sober minds process this kind of information and share it in their social networks, but also how stressed minds do," says Pruessner, a Professor in Clinical Neuropsychology working at the Reichenau Centre of Psychiatry, which is also an academic teaching hospital of the University of Konstanz.

To do this, researchers had participants read articles about a controversial chemical substance, then report their risk perception of the substance before and after reading the articles, and say what information they would pass on to others. Just prior to this task, half of the group was exposed to acute social stress, which involved public speaking and mental arithmetic in front of an audience, while the other half completed a control task.

The results showed that experiencing a stressful event drastically changes how we process and share risk information. Stressed participants were less influenced by the articles and chose to share concerning information to a significantly smaller degree. Notably, this dampened amplification of risk was a direct function of elevated cortisol levels indicative of an endocrine-level stress response. In contrast, participants who reported subjective feelings of stress did show higher concern and more alarming risk communication.

"On the one hand, the endocrine stress reaction may thus contribute to underestimating risks when risk information is exchanged in social contexts, whereas feeling stressed may contribute to overestimating risks, and both effects can be harmful," says Popovic. "Underestimating risks can increase incautious actions such as risky driving or practising unsafe sex. Overestimating risks can lead to unnecessary anxieties and dangerous behaviours, such as not getting vaccinated."

By revealing the differential effects of stress on the social dynamics of risk perception, the Konstanz study shines light on the relevance of such work not only from an individual, but also from a policy perspective. "Coming back to the ongoing COVID-19 pandemic, it highlights that we do not only need to understand its virology and epidemiology, but also the psychological mechanisms that determine how we feel and think about the virus, and how we spread those feelings and thoughts in our social networks," says Gaissmaier.