March 2, 2007 -- Facing a personal dilemma? Don't stay up all night mulling it over; sleep deprivation may cloud your moral judgment.
That's according to a U.S. Army study on sleep deprivation and moral judgment.
The study comes from Maj. William Killgore, PhD, and colleagues at the Walter Reed Army Institute of Research in Maryland.
They studied 26 healthy, active-duty military personnel asked to deal with fictional dilemmas before and after staying awake for 53 consecutive hours.
"Most of us are confronted with moral dilemmas nearly every day, although the majority of these choices are minor and of little consequence," Killgore says in an American Academy of Sleep Medicine news release.
"Our results simply suggest that when sleep deprived, individuals appear to be ... slower in their deliberations about moral personal dilemmas," says Killgore.
The study appears in the journal Sleep.
Study participants included 21 men and five women. They were 20-35 years old (average age: 25).
First, participants took an emotional intelligence test. Emotionally intelligent people are aware of their emotions and the emotions of others, and they're good at using that information to shape their decisions and behavior, Killgore's team notes.
Next, participants read 30 dilemmas. Each dilemma ended with a solution that participants had to judge as appropriate or inappropriate.
The dilemmas were either nonmoral, moral but impersonal, or moral and personal.
The nonmoral dilemmas presented a solution that wouldn't seriously hurt anyone.
The moral impersonal dilemmas presented a solution that would redirect inevitable harm from one group to another, without requiring the participant to directly inflict harm.
The moral personal dilemmas presented a solution that forced the participant to directly inflict serious bodily harm or death on someone in order to help save someone else.
The dilemmas were fictional; participants didn't actually face the situations in real life.
When the researchers timed participants as they judged the dilemmas, they found judgment times were similar for each type of dilemma.
Sleepless for 53 Hours
In addition, participants with high scores on the emotional intelligence test weren't any slower in judging the moral personal dilemmas when sleep deprived.
They also judged these dilemmas the same way before and after sleep deprivation.
However, participants with average or low emotional intelligence tended to waver in their judgments on the moral personal dilemmas. Specifically, they became more lenient, judging solutions they had considered "inappropriate" before sleep deprivation as "appropriate" when sleep deprived.
Sleep deprivation may affect certain brain areas, and people with high levels of emotional intelligence may be less affected by that, the researchers suggest.
Killgore's team stresses that the findings don't prove sleep deprivation leads to poor moral judgment.
"Whether these judgments were morally 'right' or 'wrong' in any absolute sense was not addressed," the researchers write.
Caffeine didn't affect the results, the researchers write.
It's not clear whether the findings apply to civilians, Killgore and his colleagues note.