British scientists claim to have pinpointed at least one of the causes of your bad moods: your smartphone.

Nearly a third of notifications from your smartphone trigger negative emotions, making you feel more hostile, upset, nervous, afraid and ashamed than you were before picking up your phone, according to a newly released study from Nottingham Trent University.

According to the researchers, the main culprits were notifications related to work, as well as those related to phone updates and Wi-Fi availability.

“It is clear that social notifications make people happy, but when they receive lots of work-related and or non-human notifications, the opposite effect occurs,” Dr. Eiman Kanjo told UK newspaper The Telegraph.

Indeed, notifications from friends buoyed participants’ moods, and helped foster feelings of belonging to a group.

To gather the data, the scientists invited participants to download an app that would collect information about their phone’s notifications over a five-week span.

In all, the scientists observed 50 participants as they received over half a million notifications over a five-week span, self-reporting their reactions in a questionnaire three times a day.

This story originally appeared in the New York Post.