Study: Just being slightly sleepy can make you angry in no time

Sleepiness has been found to intensify feelings of anger, especially under frustrating conditions (like, say, work!) A new study from researchers at the Iowa State University published in the Journal of Experimental Psychology: General focuses on sleepiness and how it leads to anger and hostility.

Losing just a couple hours of sleep over two days was enough to cause significant amounts of anger, they found.

Sleepy anger

Researchers tested 142 subjects: one half on a good night’s sleep, and one half on a moderate amount of sleep restriction. Sleep-restricted subjects got 5 or 6 hours of sleep a night – the type of sleep loss often experienced in everyday life.

The next day, the sleepy subjects were provoked with different types of noise as they performed the task of rating consumer products, and their anger levels measured.

Do not disturb

“In general, anger was substantially higher for those who were sleep restricted,” said Zlatan Krizan, researcher and professor of psychology at University of Iowa. “We manipulated how annoying the noise was during the task and as expected, people reported more anger when the noise was more unpleasant.”

Sleep-restricted subjects also reported more anger without the noise, he added.

Angry or not, “losing sleep leads to a complex, almost limitless set of consequences,” according to the study. In short, if you continually miss out on sleep, you never know where you may end up.