Stress and Human Performance


If you examine the research literature on the topic of “psychological stress” you will find that there is a lot of disagreement on a definition of that term. However, there is almost total agreement that while stress can have positive effects in some situations, it can also have very negative effects on human performance in other situations.  For our purposes we will accept the Mirriam-Webster definition of stress as “a state of mental or emotional strain or tension resulting from adverse or very demanding circumstances.”  While this definition ignores the positive effects of moderate stress that research shows is needed for motivation and action, it does describe a state that we all have experienced, and some of you may be experiencing right now.  Stress comes in several forms, including acute stress (in an emergency situation), chronic stress (from factors such as job, family, etc), stressful life events (e.g., divorce, death of a loved one, etc) and just those daily hassles (e.g., traffic, arguments, etc).  The one common thing in all of these types of stress is that they originate as a response to context.  There’s that word again….the one that we seem to talk about in just about all of our blogs.  Not only is stress a response to various aspects of our context, stress becomes part of our context and then impacts our performance and the decisions that we make.  Stress is our physiological response to our interpretation/appraisal of our context and it directly impacts cognition, social behavior and general performance.  Salient contextual factors such as noise, peer pressure, authority pressure, task load and time pressure have been shown to have detrimental impact on performance. Research is clear that high levels of stress cause us to narrow our attention span, decrease search behavior, react slower to peripheral cues, reduce our vigilance, degrade problem solving and rely on over learned responses that may or may not be best in the current situation.  In other words, we tend to make poorer decisions that can lead to failure and even injury.  Stress also causes us to lose our team perspective and it decreases the frequency with which we provide help to others.  This is especially impactful when working in high risk environments where watching your partners back and intervening when necessary is critical to maintaining safety and stopping unsafe actions and incidents.

So how do we deal with this so that stress doesn’t negatively impact performance?

We suggest a two-pronged approach involving (1) control of context and (2) control of how we interpret context in the moment.  Keep in mind that we are talking about normal stress reactions that we all experience, not pathological reactions that are best dealt with by trained therapists.  Let’s start with control of context and let’s set that context in the workplace.  In the workplace, context is, to a large extent under the control/influence of supervision and management.  So what should supervisors and managers do?  They should attempt to set realistic production objectives with realistic time constraints to create a context that help control stress produced by task load and time pressure.  They should minimize where possible the amount and duration of noise.  They should make sure that employees are trained so that they have the knowledge and skills required to meet those production objectives.  Simply being aware of the negative impact of stress, the relationship between stress and context, and the impact that they personally can have on that context will go a long way in stress control.  But what about how the individual interprets context in the moment.  Simple awareness that we can control stress reactions through our interpretation of context is a very good starting point.  In our February 25, 2015 blog we discussed how we are “Hardwired to Jump to Conclusions”.  In that discussion we saw how research supports the involvement of two different cognitive “Systems” in decision making and that System 1 tends to make quick decisions based on past experience and System 2 tends to be more rational and analytic.  Research demonstrates that the more stress we are experiencing, the more likely we are to engage in System 1 thinking which increases the likelihood that we will make less informed and perhaps less effective decisions.  We suggest that you use the initial physiological stress reactions as a “trigger” to stop, engage System 2 cognitive functions and evaluate your current context to determine what, if anything, can be done to create a different, less stressful context.  But what if you can’t change the context?   As we all know, there are times when we have a deadline and we are stuck in traffic and we can’t change that.  But we can stop, engage System 2 thinking, slow down our physiological response, realize that stressing out is not going to change the situation and figure out the best way out of this situation.  This of course takes practice and there are times when we won’t be successful, but understanding stress and how to respond to it can become an effective strategy to help us perform effectively in stressful conditions.