American researchers asked themselves whether there was a link between the emotions displayed in our faces and the level of stress experienced during a stressful situation. They exposed 92 adults to a particularly difficult arithmetic task, inspired by the Trier Social Stress Test, a validated psychosocial task used frequently in laboratories. They measured cardiovascular activity, variations in salivary cortisol levels, they asked participants to rate the emotions they felt during the task and finally they quantified their facial expressions with a video that was taken during the test. Despite the big inter-individual variability, the analyses reveled that fear expression during the task (like the combination of elevated and frown of the eyebrows) can predict an increased stress response, while expression of indignation was associated with a lower stress response. It seems that a person that is trained to analyze facial expression could easily detect our stress level when we are exposed to a difficult task. Will facial expression analyses be a technique used by recruit?
Title: Facial expressions of emotion reveal neuroendocrine and cardiovascular stress responses.
Authors: Jennifer S. Lerner, Ronald E. Dahl, Ahmad R. Hariri, Shelley E. Taylor.
Journal: Biological Psychiatry (2007) vol. 61 pp. 253-260