There’s nothing quite like a slow-loading webpage or finicky payment portal to get those angry juices flowing.

But new research shows that being mad in front of the computer screen doesn’t just affect your head. Impatience comes out in your hands, too.

The research, set to be published in the MIS Quarterly in March, found the ways computer users move their mouse is a pretty honest measure of how they’re feeling. By monitoring 270 users around the globe in real-time, researchers found that they could predict negative emotions like frustration, sadness, fear and depression with more than 80% accuracy.

The researchers tracked people as they moved their mice while completing tasks on the computer like paying bills or doing research. Some of the experiments were rigged to frustrate participants by showing them slow loading pages during things like timed tests.

The researchers found that people who were upset navigated their screens differently. Compared to others, they moved their cursors around more slowly in longer and jerkier lines.

Study co-author Jeffrey Jenkins, an assistant computer science professor at Brigham Young University, says the findings fall in line with other research that often relies on sensors, microphones, and cameras to assess emotions. But now he knows that he merely needs a mouse or a touchpad to get pretty good idea of how people feel.

Jenkins says the goal is to “try to use computers and sensors to learn about the user, to create a better user experience.”

Some of the research has already been patented for assessing how well people interact with websites. But the research isn’t just helping developers fix bugs, Jenkins says he also hopes people will use the data to create websites that can respond to user movements by delivering tailored interfaces that match user moods and abilities.

As people shift to mobile devices, Jenkins said he now wants track how using touch screens is related to emotions by tracking measurements from accelerometers inside phones and tablets. He will also look at how people change how they hold their devices based on their mood. So take a deep breath… and keep on clicking.

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