The Science of Stress: Part 1

By Donovan Makus

Stress. Something we’ve no doubt heard about, read about and, likely, personally experienced. As deadlines start to approach and midterms are written, stress levels are at an all-time high. While our personal experience with stress is a good starting point for understanding it, there is also a rich scientific library of literature associated with stress and a great deal of research devoted to understanding, managing, and reducing it. In this week’s article, we’ll look at the scientific definitions of stress, models and theories of stress, how stress works on a biological level, and where it comes from. In the next issue, we’ll look at scientifically-proven coping and stress reduction techniques to help us manage our stress in a healthy way.

When we say we’re “stressed,” we usually mean a subjective mental experience related to how we feel. In fields like engineering, stress refers to more concrete occurrences and can be directly measured, such as the stress a bridge experiences when a certain load is placed on it. Additionally, the types of human stress vary, ranging from chronic stressors, such as fear of the future, to acute stressors, such as a midterm next week. Differentiating between these stressors will have implications for looking at coping strategies in part 2. While there is a cognitive component to stress, cognition isn’t detached from biology. Human stress has actual biological implications and mechanisms through which it acts upon us. When looking at stress, it’s useful to use the biopsychosocial model that has taken clinical and social sciences by storm. This model breaks down the factors of a phenomenon into biological, psychological, and social aspects, as the name suggests. To look at the science of what causes stress and how it affects us, we’ll start with the biological basis.

There are strong biological indicators and mechanisms associated with stress. To quickly review intro psychology and human physiology, stress is associated with the activation of our sympathetic nervous system (SNS)–our “fight or flight” system–with its neurotransmitters leading to noticeable effects on our body. Longer term stress responses are associated with hormones such as cortisol. When activated, our SNS affects numerous body systems from blood flow to digestion. On its own, the SNS is a good thing, giving us an extra edge when facing external threats such as a dangerous wild animal, and acts similarly to an “emergency power” mode you may find on some machinery, which allows you to bypass the normal operating limits. However, just as running an engine above its normal operating range may be fine once or twice in an emergency, long-term overuse of the max power causes wear and tear. Unfortunately for this analogy, engines can usually be replaced while our bodies cannot (yet). Long-term stress causes immune system suppression, weight gain or changes in weight distribution (high levels of cortisol are associated with belly fat), and reduced mental functions. The fact that these biological responses are consistent in response to different types of stressors forms the basis for one of the theories of stress management: the General Adaptation Syndrome view, which holds that all stressors lead to the same alarm, resistance, and exhaustion patterns. We’ll look at this in more detail in the next issue.

While it’s useful to understand the biological basis of stress, viewing stress solely in terms of neurotransmitters, systems, and physiological terms misses the key steps of cognitive interpretation that shape how our stress response is activated and how we will react. How we interpret potential stressors matters. If you are anything like me, you probably felt a little nervous sitting down in your first university class or midterm, but now, going to class isn’t a big deal, and while midterms still generate some stress, it’s not to the same degree as in our first years. Similarly, someone doing their first freefall skydive will likely experience a much greater stress response than a jumpmaster who has completed thousands of jumps. Our past experience isn’t the only factor affecting our cognitive appraisal of stressors, however, as our level of control also affects our stress levels. As covered in intro psych classes, there are two categories of control outlined: internal, when we believe we can control stress, and external, when we view control as falling outside ourselves. People who hold an external locus of control (the degree to which people believe that they have control over the outcome of events in their lives) are more vulnerable to stress and tend to externalize it. Related to the concept of locus of control is our self-efficacy, which is how effectively we feel we can handle a task. In the case of stress, someone who high self-efficacy would be more confident in their ability to handle their stress, leading them to feel better than someone who feels completely overwhelmed as they perceive their stress as being beyond their control.  

The final aspect in the biopsychosocial model is the social aspect of stress. At our core, we are social creatures, and living in social communities adds yet another dimension to stress. Stress can result from social factors, such as living in an economically depressed area or interactions with family or within peer groups. It’s useful to draw a line between the higher-level structural social stressors, such as being an oppressed minority group, and more immediate social factors, such as a difficult work environment or home life. Together, these social factors play a key role in both presenting stressors, but also affect how we cope with stress.

Looking at stress is the first step to understanding it. Our collective knowledge about stress continues to evolve as further research is completed and we undergo societal changes associated with new forms of technology. Hopefully, this week’s look at stress hasn’t left us feeling overwhelmed or stressed ourselves since next week we’ll look at stress management.

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