Happy? Sad? Sleep Deprivation Blurs the ‘Read’

Business leaders who rely on their people-reading skills, take note: A recently released study led by William D.S. Killgore, University of Arizona professor of psychiatry, psychology and medical imaging, found that study participants had a harder time identifying facial expressions of happiness or sadness when they were sleep deprived than when they were well-rested. While the difference in performance was not overwhelming, it’s enough that it could have a significant impact in critical social interactions, Killgore says.

“As a society, we don’t get the full seven to eight hours of sleep that people probably need to be getting. The average American is getting a little less than six hours of sleep on average, and it could affect how you’re reading people in everyday interactions,” says Killgore. “You may be responding inappropriately to somebody 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 sleepy participants’ ability to interpret facial expressions of other emotions — anger, fear, surprise and disgust — was not impaired, however. Killgore believes that’s likely because we’re wired to recognize those more primitive emotions in order to survive acute dangers.

The data used in the study, “Sleep Deprivation Impairs Recognition of Specific Emotions,” is part of a larger research effort on sleep deprivation’s effects on social, emotional and moral judgment. Killgore began the project while working as a research psychologist for the U.S. Army. The recent study supports an earlier one, published by Harvard’s Seung-Schik Yoo and colleagues, which showed that when people are sleep deprived, a disconnect occurs between the prefrontal cortex and the amygdala — one of the key emotionally responsive areas of the brain.