Seeing a rude interaction in the morning—otherwise known as a regular weekday for most commuters—could set you up for a gloomy and unproductive work day, according to new research published in the Journal of Applied Psychology.

Researchers from the University of North Carolina, Wilmington, recruited 81 people from an executive MBA course, working in fields like security, medicine and business, to participate in the experiment. For ten consecutive work days, participants completed surveys twice a day, recorded their mood in the morning and reflected on their day before bed, Alex Fradera writes in an article about the study in the British Psychological Society research digest.

The morning survey included a link to a video that participants were told to watch as part of a critical thinking task, but it was actually meant to expose them to different types of interactions—either rude or pleasant. The “rude” video showed interactions between people where they avoided eye contact or used unfriendly language. On the mornings they watched the rude video, participants also played a word game where the answers to the questions were phrased in rude language, such as “she always bothered him,” according to Fradera.

On days when people watched the rude video, they reported experiencing more rudeness in their workplaces. It had a pretty significant impact on their overall days, too: participants reported avoiding interactions with other co-workers, being less productive in working towards their goals and daily tasks and feeling less ownership of their responsibilities on the days that started with rudeness, Fradera writes.

Interestingly, not everyone was equally affected by watching the rude video. Prior to the study, participants took a questionnaire that measured qualities “related to confidence and emotional stability,” Fradera writes, like self-esteem and feeling capable. People who scored higher in that evaluation were “immune from the rudeness manipulation, neither perceiving more rudeness during their workday nor suffering the adverse effects that the rude video appeared to provoke in their less confident colleagues,” Fradera writes.

While you can’t control how other people act in the mornings, you can do things to boost your self-esteem and emotional stability, like practicing meditation, journaling, or speaking to a therapist, to help change how you react to the rudeness around you.

Read more about the study here