Long term stress is linked to pessimistic personality traits, according to a study published in the Journal of Research in Personality.

Studies over the past few decades have found that a person’s personality can change across a person’s life. The current study examined the relationship between stress and personality changes. Stressors are understood to be circumstances or situations that are considered intimidating or taxing, or exceed a person’s ability to cope. When a person is exposed to a stressor, a person will display a stress response; this study focused on long term stress, rather than short term stress (think fight-or-flight). Long term stress involves the sympathetic nervous system, the innate immune system and the hypothalamic-pituitary-adrenal axis (also known as the HPA),. The intensity of the response to stress is dependent upon how a person perceives the stressor; if the stressor is seen as highly threatening, then the response will be strong, and vice versa.

Stress has been connected to the development of anxiety disorders and depression, which in turn can encourage personality changes. Major life events can also prompt changes in personality. Therefore, it is also possible that more long term stress would be able to induce a personality change, for this study, specifically pessimism.

In this study, 332 participants completed different surveys for five weeks in a row, and were encouraged to consider the previous week in their responses. Researchers utilized the most widely used scales for both stress (10-item Perceived Stress Scale) and pessimism (items taken from the Life Orientation Test-Revised). This research is the first to show that stress and pessimism are linked. Interestingly, researchers noticed decreases in levels of perceived stress as well as pessimism. This may be due to the unexpected benefits of participating the study, such as the possibility that expressing stress levels may be cathartic. The changes in pessimism in five weeks are supported by previous research showing that personality changes can occur in such a short timeframe.

It is essential to note certain limitations of the current study. The study was based on participants reporting their perceived stress and pessimism, which could lead to intentional or unintentional dishonesty from participants. Stress may also influence other personality traits, like conscientiousness and extraversion, which may in turn affect pessimism. Additionally, personal growth after a traumatic event may influence the development of positive personality traits, not just negative ones like pessimism. The last limitation the study addresses is the temporal relationship between stress and pessimism. As always, correlation does not imply causation; being pessimistic does not necessarily mean that a person perceives more stress, and more stress does not make a person more pessimistic according to the research presented in this study.

This study is the first to show the link between perceived stress and pessimism, but further research is necessary to determine the chronological ordering of these effects, as well as how stress affects other personality traits. Finally, it is imperative that these research efforts are able to make meaningful and relevant statements about human health. With an ever-increasing need for effective mental health treatment, future research should address the relevance of these stress-personality dynamics for human health.