Physical stress from interruptions in the workplace

ETH researchers used an experiment in a simulated group office environment to show for the first time that the body produces more stress hormones when people are repeatedly interrupted at work. And yet the subjects did not experience a steady increase in their consciously perceived feeling of psychological stress.

According to the Job Stress Index 2020 compiled by the Swiss Health Promotion Foundation, a Swiss health foundation, almost a third of the Swiss workforce suffers from work-related stress. Should this stress become chronic, it can lead to states of fatigue, which have a negative public health impact and create significant economic costs.

The goal: a digital early warning system

In the Mobiliar Lab for Analytics at ETH Zurich, an interdisciplinary team is working to prevent such states of exhaustion by developing a digital early warning system that uses machine learning to detect stress in the workplace in real time.

Our first step was figuring out how to measure the effects of social pressure and interruption – two of the most common causes of stress in the workplace. ”

Jasmine Kerr, psychologist

Kerr is driving the project forward together with mathematician Mara Nägelin and computer scientist Raphael Weibel.

The three PhD students are all lead authors on a recent study, details of which were published in the journal Psychoneuroendocrinology. They used a university platform to recruit 90 participants who agreed to take part in a nearly two-hour experiment. For the experiment, Kerr, Nägelin and Weibel converted the Decision Science Laboratory at ETH Zurich into three group office environments. Each workstation was equipped with a chair, a computer with a monitor, and kits for collecting saliva samples.

Participants played the roles of employees of a fictional insurance company and were asked to perform typical office tasks, such as B. Enter information from handwritten forms and make appointments with customers. Meanwhile, the researchers observed their psychobiological reactions. At a total of six points during the experiment, the participants rated their mood using questionnaires, while a portable EKG device continuously measured their heartbeat. The researchers used the saliva samples to measure levels of the stress hormone cortisol.

In line for a promotion

For their experiment, the researchers divided the participants into three groups and exposed each group to a different level of stress. All groups received the same workload. In the middle of the experiment, all participants were visited by two actors disguised as representatives of the insurance company’s HR department. For the participants in the control group, the actors conducted a sales talk while in the two stress groups they pretended to look for the most suitable candidates for a promotion.

The difference between the two stress groups was that the participants in the first group stopped working just to take samples of their saliva. However, the participants in the second stress group had to deal with additional interruptions in the form of chat messages from their superiors urging them to request information.

Almost twice as much cortisol

When analyzed, the data showed that asking participants to apply for a fictional advertisement was enough to raise their heart rate and trigger the release of cortisol. “The participants in the second stress group released almost twice as much cortisol as the participants in the first stress group,” says Nägelin. Weibel adds, “Most of the work interruption research we’ve done to date has focused only on its impact on performance and productivity. Our study shows for the first time that they also affect the levels of cortisol a person releases, in other words, they actually affect a person’s biological stress response. ”

What surprised the researchers was the participants’ subjective responses to perception of psychological stress. They observed that participants in the second stress group who were interrupted by chat messages stated that they were less stressed and in a better mood than those in the first stress group who did not have these interruptions. Interestingly, both groups found the situation to be equally challenging, the second as less threatening.

The researchers concluded that the release of cortisol triggered by the additional interruptions mobilized more physical resources, which in turn led to better emotional and cognitive response to stress. It is also possible that the interruptions distracted participants from the impending social stressful situation, which meant that they felt less threatened and therefore less stressed.