It's common knowledge that going for a while without sleep can make you moody and irritable. But a new study proves that grouchiness isn't the extent of the problem. Sleep deprivation doesn't just mess up your emotions; it reduces your ability to assess and react to the emotions of others. In other words, it decreases your emotional intelligence--your EQ.

How Sleep Loss Affects your Emotions

Being tired actually changes how we perceive others, ourselves, and our surroundings.

Impaired Threat Perception

Research from UC Berkeley¹ published earlier this month analyzed an important part of how we interact with others: how we perceive threats. 

In the study, subjects were shown pictures of people making faces ranging from friendly to aggressive--once after a full night of sleep, and once after 24-hours of wakefulness. Researchers analyzed MRI scans and heartbeats of the participants to see how they responded on a gut level to the pictures. 

They found that when sleep-deprived, subjects were less able to distinguish between the inviting and hostile faces. Instead, they were more likely to perceive faces with any expression as threatening. So if you feel moody running on little sleep, it could be because you're sensing the rest of the world as unfriendly too.

This discovery has implications for how humans interact with each other. Impaired threat perception could pose problems for people working in high-pressure or emotionally intense situations, like soldiers on duty, a sleep-deprived mother responding to a crying baby, or an overworked doctor dealing with patients.

But there is some good news...the researchers also found that REM sleep improves emotional sensitivy! In fact, subjects who engaged in more REM sleep during their full night of sleep were better at accurately sensing emotions the next day.

Insensitivity 

But recognizing threatening signs in others isn't the only cost of cutting down on zzzs...in fact, sleep deprivation blunts your ability to recognize lots of emotions. 

In a similar study², scientists showed test subjects photographs of human faces and asked them to rate the expressions on how happy, sad, or angry they appeared. When sleep deprived, participants were markedly less accurate at detecting happy and angry emotions. This means that not only does sleep deprivation mess up our threat-response, but it reduces our ability to respond to positive, rewarding stimuli.

Worse People Skills

Not surprisingly, when we can't accurately gauge other people's emotions, our social savvy goes downhill. That's the upshot of a study³ that made an across-the-board assessment of how our emotions change when we're tired. It found that sleep-deprived subjects displayed lower self-esteem, asertiveness, independence, empathy, quality of interpersonal relationships, stress management, impulse control, and positive thinking. That's a lot of negatives!

In other words, when we're not sleeping enough, everything about our emotional state--our self-perception, our attitude, and the way we see others--suffers. 

So whether you're a businessman who makes a living from interacting with clients, or just looking to improve your relationships with friends and family, start by treating yourself to a good night of sleep!

What do you act like when you're tired? Do you get grumpy, moody, or even hyper? Let us know in the comments!

Sources:

1) Goldstein-Piekarski, Andrea N. et al. "Sleep Deprivation Impairs the Human Central and Peripheral Nervous System Discrimination of Social Threat." Journal of Neuroscience.

2) Van der Helm, Els et al. "Sleep Deprivation Impairs the Accurate Recognition of Human Emotions." Sleep Journal.

3) Killgore, William D. S. et al. "Sleep deprivation reduces perceived emotional intelligence and constructive thinking skills." Sleep Medicine.