A bad night’s sleep can leave you more than grumpy. It can damage your personal relationships or your relationships at work.
Lack of sleep affects your ability to recognise whether people around you are happy or sad so you may misinterpret or not be very sympathetic.
Your survival instinct, however, will still warn you when someone near you is angry, fearful, surprised or disgusted.
Sleepy people have trouble interpreting facial expressions, according to the study led by University of Arizona psychologist William Killgore.
Social emotions like happiness or sadness are the first casualties if you have been sleep deprived.
“As a society, we don’t get the full seven to eight hours of sleep that people probably need to be getting. It could affect how you’re reading people in everyday interactions,” Killgore says.
“You may be responding inappropriately to somebody that you just don’t read correctly, especially those social emotions that make us human. Or you may not be as empathic.
‘Your spouse or significant other may need something from you and you’re less able to read that.
“It’s possible that this could lead to problems in your relationships or problems at work. “
To me, that is one of the biggest problems — how this affects our relationships.”
The good news is that no matter how sleep you will still be aware of other emotions like fear and anger which could pose a threat to your safety.
“If someone is going to hurt you, even when you’re sleep deprived you should still be able to pick up on that,” says Killgore. “Reading whether somebody is sad or not is really not that important in that acute danger situation, so if anything is going to start to degrade with lack of sleep it might be the ability to recognize those social emotions.”
Killgore explains that in simplistic terms the part of your brain that controls your emotions and the part that sees the emotion in faces basically lose their ability to communicate to each other when you haven’t had enough sleep.
“We wanted to test that out and see if it plays out in terms of how people read facial expressions — and, in fact, it looks like it does,” he adds.
The study is published in the journal Neurobiology of Sleep and CircadianRhythms.