Losing out on a good night's rest does more than make us feel like a train wreck the next day, it affects our relationships too, new research shows.

Research conducted by UC Berkley psychologist Amie Gordon showed that when we deprived of sleep, we tend to be selfish, are less likely to say “thank you”, and generally take our partners for granted.

"Poor sleep may make us more selfish as we prioritize our own needs over our partner's," Gordon explains in an article by the Daily Mail.

During the study, Gordon asked 60 couples between the ages of 18 and 56 to record how many hours they slept each night as well as how appreciative they felt towards their significant other.

The couples were then asked to work together on a problem-solving activity. The researchers videotaped their interactions.

Results showed that well-rested couples encouraged each other more and worked better on the tasks than their sleep-deprived counterparts.

The couple's diary entries correlated with these findings, with well-rested couples displaying regular appreciation and affection toward their partners, whereas those who slept badly the night before showed less gratitude.

"You may have slept like a baby, but if your partner didn't, you'll probably both end up grouchy," Gordon notes.

A 2011 report from the Britain's Mental Health Foundation showed that only 40 percent of adults get enough rest and sleep well. The report also revealed that insomniacs were four times more likely to suffer from relationship problems and three times as likely to suffer from mood swings.

Most adults need between seven and eight hours of sleep each night to function well the next day, though experts say that amount can vary for an individual.