Marta M. Rodríguez
University Professor Department of Psychobiology, University of Valencia
To a greater or lesser extent, stress is part of our lives. At first, this statement should not seem like a fact that causes concern. Although the word itself has acquired a clear negative connotationis a highly adaptive response that prepares the body to react to any threat.
When we notice the racing heart rate, rapid breathing, focused attention, and sweaty palms, it’s because the activation the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic system have prepared the body for struggle the huir.
The negative consequences of stress appear when it is maintained for Long periods of time and the state of alert becomes chronic. Unfortunately, this response pattern is very common in our daily lives. The extraordinary cognitive capacity of the human being allows us to be able to anticipate and worry (even more than worry) about an infinite number of possible threats.
Traditionally, the focus of research has been focused on studying the negative consequences of stress in those individuals who suffer from it. However, there are very few works that evaluate the possible stress-inducing effects in subjects who are only witnesses to the situation.
Witnesses to the suffering of others
To study this phenomenon, researchers often use tests such as the Trier social estrés test (TSST), where the participant must perform tasks that are perceived as stressful by the majority of the population.
The volunteer has to prepare a small oral presentation in the context of a job interview. To do this, he is provided with a sheet that is then suddenly removed. Throughout this exposition, the supposed judges remain with expressionless faces. In the end, the test includes a surprise task consisting of a series of mental arithmetic exercises.
As expected, the test induces a stress response that is reflected in several physiological markers: increased heart rate, sweating, increased levels of stress hormones (cortisol), etc.
Recent research shows that when a person watches a TSST participant go through this testing odyssey, they experience a response quite similar to that of the subject taking the test. That is, we not only suffer from our own stress, but we are also affected by the one that the others pass.
Undoubtedly, being able to feel in one’s own flesh the suffering of others has a clear evolutionary meaning, since it can be a very advantageous strategy when it comes to learning to avoid possible dangers and behaviors that harm us. We understand much better now the popular saying that states “when you see the neighbor’s beard cut, put yours to soak.”
Mice distressed by the defeat of a fellow
Vicarious stress is not an exclusive phenomenon of the human being. Initial studies showed that when mice observe an aggressive encounter with a conspecific, they exhibit behaviors typical of freezing. Interestingly, they are much more marked if the subject is socially related to them (cage mate, member of the same litter, etc.).
More recent research has shown that witnessing a confrontation between two male rodents for dominance of a territory induces a complete response from the witness. sympathetic system and the HPA axis. That is, the mice also suffer stress after witnessing the defeat of another mouse and experience some of its adverse effects.
Like the physically defeated males, the rodents that witnessed this social defeat show a decrease in the social interaction, an increase in anxiety, depressive behaviors and suffer more intensely from the reinforcing effects of drugs such as alcohol or cocaine. It was even observed that they experienced an inflammatory profile similar to that of stressed mice.
These findings are highly relevant to the study and treatment of disorders, such as obesityaddictions and various mental illnesses, in which stress is the greatest risk factor.
Society must understand that not only the direct victims receive the negative impact of stress. War refugees, the classmates of a victim of bullying or the children of a couple in which gender violence is exercised witness very distressing situations that can have a strong impact on their psychological and emotional development.
