Sleep deprivation is tied to a whole host of health effects, from increased anxiety, to decreased bone mineral density, to consuming more calories. And apparently, it could also take a toll on your relationship.
A new study from researchers at the University of California, Berkeley, found that sleep deprivation could have an effect on our expressions of gratitude -- in turn straining relationships by making people feel like they are being taken for granted.
"Poor sleep may make us more selfish as we prioritize our own needs over our partner's," study researcher Amie Gordon, a psychologist at the university, said in a statement. The findings were presented at a meeting of the Society for Personality and Social Psychologists; because they have yet to be published in a peer-reviewed journal, they should be considered preliminary.
The study was split up into three parts, and included more than 60 study participants whose ages ranged from 18 to 56. For the first part, study participants were asked to list five things they were grateful for as their previous night's sleep quality was analyzed by the researchers. People who hadn't gotten a good night's rest felt less grateful after listing the five things, compared with people who had had a good rest.
In the second part, the study participants were asked to record how well they slept for two weeks, as well as how grateful they felt. Researchers found an association between decreased feelings of gratitude and poor sleep. And in the third part, researchers analyzed the sleep and gratitude of couples to find an association between poor sleep and fewer feelings of appreciation from the other person.
"Poor sleep is not just experienced in isolation," Gordon said in the statement. "Instead, it influences our interactions with others, such as our ability to be grateful, a vital social emotion."
And a bad night's rest may not only harm your relationship with a partner -- it could also harm your ability to form new relationships, past research suggests. A Swedish study from last year suggested that sleep deprivation can impact how approachable we seem to other people.
For more surprising signs you need more sleep, click through the slideshow: