Lack of sleep can affect people鈥檚 moral judgement, a new study shows. The findings could have implications for people in positions of responsibility, whose decisions often have life or death consequences, such as overworked medical professionals and sleep-deprived soldiers.
William Killgore and colleagues at the Walter Reed Army Institute of Research in Silver Spring, Maryland, US, set up an experiment with 26 healthy adults, all of whom were active-duty military personnel.
The participants were presented with a variety of hypothetical dilemmas, first when well rested and later, after staying awake for 53 hours. Situations included complex moral quandaries such as having to choosing whether or not to let one person die in order to save the lives of several others. Less weighty dilemmas without a moral component were also included, such as 鈥渋s it OK to substitute ingredients in a chocolate brownies recipe?鈥�
Advertisement
While participants did not become less 鈥渕oral鈥� when sleep deprived, they did require two seconds longer on average to answer complex moral questions, Killgore says. However, questions without a moral component did not take longer to answer after participants were kept awake.
Asleep at the wheel
The findings, along with previous brain-imaging studies, suggest that sleep deprivation has a particularly debilitating effect on decision-making processes that depend heavily on emotion. 鈥淲hen people go for more than 24 hours without sleep there are dramatic decreases in brain activity in the prefrontal cortex [the area of the brain involved in processing emotions and decision-making],鈥� says Killgore. 鈥淚t basically goes to sleep.鈥�
Sleep deprived participants also showed slight shifts in what they deemed appropriate actions compared to when they were well-rested. The changes were more pronounced in individuals who scored lower in 鈥渆motional intelligence鈥� tests. Killgore believes that those with a lower emotional capacity to begin with may have less resistance to the affects of sleep deprivation.
Judy Illes at the Center for Biomedical Ethics at Stanford University, California, US, says the study鈥檚 implications are profound. 鈥淢oral judgements are perhaps the most complex decisions that people have to make, decisions that are laden with personal, social, religious, and cultural values,鈥� she says.
鈥淲e don鈥檛 want tired irritable soldiers making bad decisions that endanger themselves or others that are not a threat to them. Nor do we want health care providers who are unable to make quick medical decisions on behalf of their patients.鈥�
Both Illes and Killgore are quick to note that further research, including brain imaging, should be conducted as laboratory results do not always translate to real world situations.
Journal reference: Sleep (v 30, p345)
