Nobody likes being interrupted when they're busy, let alone being randomised at work when they're trying to get important jobs done.
But what's going on under people's skin when workplace interruptions keep diverting workers from the task they're trying to concentrate on? An experiment in Switzerland investigated this all-too-common scenario, and found the effects of interruptions aren't always as predictable as we might think.
In the study, Kerr and her team recruited 90 participants for an experiment in which the researchers' lab was modified to mimic a real-world office environment, equipped with multiple rows of desks with computers on them.
In the experiment, the participants had to pretend they worked at an insurance company, performing various office tasks to the best of their ability, including digitising scans, computing sales numbers, and scheduling appointments.
While they were engaged in these standard sorts of office work tasks, two actors entered the room, pretending to be human resources staff, and engaged the participants in additional exercises.
Some of the participants (the control group) only had to perform a relatively simple additional task with the HR staff. The rest of the participants (in two separate 'stress condition' groups) had to perform a task that involves psychosocial stress in the form of being questioned and appraised - applying for a job promotion in the office scenario - while still getting their 'regular' work tasks done.
In both of the stress groups, participants were told to mentally prepare for a job interview and then undergo one, but the first group (stress condition 1) were only interrupted by regular questionnaires and saliva samples, while the group in stress condition 2 were additionally hammered with a series of interrupting chat messages on their computers, being asked to summarise and immediately share information on aspects of the work they were doing.
During these simulated workplace escapades, the participants had their stress levels monitored in three separate ways: filling out questionnaires on how they felt every 15-20 minutes, having saliva samples taken, and having their heart rate monitored via a continuously worn ECG device.
The results showed that, compared with the control group, the participants in the two stress condition groups (who underwent the job promotion task on top of their other office duties) experienced a raised heart rate and released more of the 'stress hormone' cortisol in their saliva – but there was still a noticeable difference between the two stress-tested groups.
"Participants in the second stress group released almost twice the level of cortisol as those in the first stress group," says one of the team, mathematician Mara Nägelin from ETH Zurich.
That's not altogether surprising, given the barrage of interruptions and stress-inducing exercises those participants had to endure in the experiment. But there was something quite unexpected in the questionnaire results from stress condition 2.
"Interestingly, the condition that experienced work interruptions showed a higher increase of cortisol levels but appraised the stress test as less threatening than individuals that experienced only psychosocial stress," the authors write in their paper.
"Exploratory mediation analyses revealed a blunted response in subjective measures of stress, which was partially explained by the differences in threat appraisal."
In other words, the participants in the experiment who you'd think had the hardest time of it (stress condition 2) actually reported feeling better in terms of their mood and feeling less stressed and threatened than the people in stress condition 1.
Just how that could be remains a bit of a mystery, but the researchers speculate that the increased interruptions, in addition to triggering more cortisol production, could have somehow produced better emotional and cognitive responses to the stress being felt.
"Increased engagement with the content of their work and the social interaction via the chat function may have elevated feelings of certainty and control," the researchers suggest.
"A second explanation could be that the chat messages acted as a distraction from focusing on the upcoming job interview."
So, in effect, the team thinks it's possible that workplace interruptions could in some ways be viewed as a positive sometimes, at least in terms of alleviating stress, because they might distract workers from things negatively impacting their mood.
Still, there's a lot we don't know about what's going on here, and the researchers acknowledge numerous limitations with the experiment they set up, which only mimicked workplace stress in a small group of participants for a couple of hours.
Future research could follow up on these leads though, and give us a better idea of how workplace interruptions may feed (and perhaps lower) our sense of stress at work.