Lack of sufficient sleep makes you selfish – Study

Aside from the health problems not having sufficient sleep may bring, experts say you might be selfish too.

A study, conducted by researchers in the US at the University of California, Berkeley, has found that losing just one hour of sleep a night could kill a person’s desire to help others, including relatives and close friends.

Published in the open-access PLoS Biology journal, the team noted that chronic sleep deficit could harm social ties and hamper the generosity instincts that strengthen society.

“Humans help each other. Empathy is a fundamental feature of humankind and one of the most powerful forces shaping the advent of modern civilizations,” Prof Matthew Walker the lead researcher said.

Adding that “This is the first study to show unambiguously that sleep loss can reduce the tendency of individuals to help one another.”

Some 160 participants were required to fill out sleep questionnaires for four days. They were asked to answer how long they slept a night and whether their sleep was interrupted.

They also answered daily survey questions to gauge their empathy and generosity.

The questionnaires presented different social scenarios such as whether they would help if a stranger stopped them to ask for directions while they were rushing to work.

The scale was from “I would ignore them” to “I would stop to help”.

Results revealed that those who had poorer quality sleep overall were significantly less generous than people who had better sleep.

It was also noted that insufficient sleep lowered the desire to help on the days when a participant had insufficient sleep.

In another experiment, 23 volunteers were kept awake for 24 hours without sleep.

They were not allowed to drink caffeine or alcohol but could browse the Internet or watch television.

The survey revealed a 78 per cent decline in self-reported willingness to help others when tired.

Prof Walker and his team then scanned the participants’ brains, which showed that having a restless night inhibits activity in the part of the brain concerned with social behaviour.

This region is known to help people understand how others are feeling or thinking and also activates empathy and kind response.

“A lack of sleep impaired the desire to help others regardless of whether they were asked to help close relatives or strangers. This means that sleep loss triggers asocial, anti-helping behaviour of a broad and indiscriminate impact,” said Prof. Walker.

An article published by the Harvard Medical School, last year, said sleeping six hours or less a night increased the chances of developing dementia by 30 per cent by the time they hit 77 years, unlike their counterparts who averaged seven hours of sleep a night.