New research confirms what our parents taught us and most of us have learned from experience: if we don't make our nightly road trip through dreamland, it's gonna make us grumpy the next day.

Iowa State University researchers say they've come up with some of the first experimental results that back up the notion that sleep loss leads to more anger, particularly when faced with frustrating situations

The study, published recently in the Journal of Experimental Psychology: General, isn't the first to connect sleep and anger, but it hasn't been clear if the link is lost sleep or disrupted sleep. The new results point to fewer hours of slumber as the culprit.

"Despite typical tendencies to get somewhat used to irritating conditions - an uncomfortable shirt or a barking dog - sleep-restricted individuals actually showed a trend toward increased anger and distress, essentially reversing their ability to adapt to frustrating conditions over time. No one has shown this before," said Zlatan Krizan, professor of psychology at Iowa State.

The researchers measured how people who were restricted to only four and a half hours of sleep per night reacted to irritating noises, compared to those who slept almost seven hours.

"In general, anger was substantially higher for those who were sleep restricted," Krizan said. "We manipulated how annoying the noise was during the task and as expected, people reported more anger when the noise was more unpleasant. When sleep was restricted, people reported even more anger, regardless of the noise."

To follow-up their results, the researchers are now collecting data to see if sleep loss can lead to actual aggressive behavior towards other people.

Published on: Dec 13, 2018