ETH researchers have 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 an equal rise in their consciously perceived
sense of psychological stress.
According to the Job Stress Index 2020 compiled by a Swiss health foundation, almost one-​third
of the Swiss workforce experience work-​related stress.
Should this stress become chronic, it can lead to states of exhaustion that have a negative
impact on public health and carry a significant economic cost.
The researchers used a university platform to recruit 90 participants, who agreed to
take part in an experiment lasting just under two hours.
To conduct their experiment, the researchers transformed the Decision Science Laboratory
at ETH Zurich into three group office environments.
Each workstation was equipped with a chair, a computer with monitor and kits for collecting
samples of saliva.
Playing the parts of employees at a fictional insurance company, the participants were asked
to perform typical office tasks, such as typing up information from hand-​written forms
and arranging appointments with clients.
While they did so, the researchers observed their psychobiological responses.
At a total of six points during the experiment, the participants rated their mood on questionnaires,
while a portable ECG device continuously measured their heartbeat.
The researchers used the saliva samples to measure the concentration of the stress hormone
cortisol.
For their experiment, the researchers divided the participants into three groups and exposed
each group to a different level of stress.
All groups were given the same workload.
In the middle of the experiment, all participants were visited by two actors prentending as
representatives of the insurance company’s HR department.
For participants in the control group, the actors staged a sales pitch dialogue, while
in the two stress groups they pretended to be looking for the most suitable candidates
for a promotion.
The difference between the two stress groups was that participants in the first group stopped
work only to have samples of their saliva taken.
But the participants in the second stress group had to contend with additional interruptions
in the form of chat messages from their superiors urgently requesting information.
Upon evaluation, the data indicated that asking participants to compete for a fictional promotion
was enough to raise their heart rate and trigger the release of cortisol.
But participants in the second stress group released almost twice the level of cortisol
as those in the first stress group.
Most research into workplace interruptions carried out to date focused only on their
effect on performance and productivity.
This study shows for the first time that they also affect the level of cortisol a person
releases, in other words they actually influence a person’s biological stress response,
What surprised the researchers were participants’ subjective responses in terms of how they
perceived psychological stress.
They observed that participants in the second stress group, who were interrupted by chat
messages, reported being less stressed and in a better mood than the participants in
the first stress group, who didn’t have these interruptions.
Interestingly, although the two groups rated the situation as equally challenging, the
second group found it less threatening.
The researchers inferred that the release of cortisol triggered by the additional interruptions
mobilised more physical resources, which in turn led to a better emotional and cognitive
response to stress.
It is also possible that the interruptions distracted the participants from the impending
social stress situation, meaning that they felt less threatened and thus less stressed.