March 14, 2007

Sleep Loss And Moral Judgment

dunkin donuts 

There's an article making the rounds that I'd like to kill off right now, before it becomes a meme, or worse, another unsupported postulate common among psychiatrists.

The title of the Reuters news story about the article (in Sleep) is this: "Sleepless nights may hinder moral judgments."  And has sentences like this: "[subjects] took a longer time to mull over the morally charged questions when they were sleep-deprived than when they were well rested. This was not the case with the more minor, non-moral scenarios."

And there's your self-serving, exculpatory imbecility of the day: a sleepless night or two turns us into lycanthropes, or at least hyenas. ("I was so tired I couldn't think straight.")   Fortunately for the existentialists, the Reuters reporter didn't actually read the Sleep article, which doesn't actually say this.

The Army study subjected volunteers to 53 hours of sleep deprivation and presented them with a battery of moral dilemma type questions ("is it morally appropriate or inappropriate to do X if Y is at stake?")

In contrast to the obvious suggestions of the Reuter's title, the study found that it took sleep deprived subjects longer to identify something as morally appropriate, but had no effect on how long it took to label it inappropriate.  In fact, relative to a non-moral issue, sleep deprived subjects were able to label something as morally inappropriate faster.

Quoting the authors:

When tested at rested baseline, participants showed no significant differences between response times for scenarios judged as “appropriate” versus those judged as “inappropriate” .... In contrast, when deprived of sleep for over 53 hours, these same participants showed significantly greater difficulty judging emotionally charged MP  (personal moral) courses of action as “appropriate” relative to judging them as “inappropriate.”

In other words, sleep deprivation made it harder for them to say something was right, but not harder to say it was wrong.  To use a metaphor, you "know" things are wrong; but you may have to judge if they are right.

The study also looked into whether people labeled something as morally appropriate more often if they were sleep deprived, i.e. were they more permissive.  First, if the subject had high emotional intelligence, sleep loss had no effect.  Secondly, having an "average" emotional intelligence lead to an increase in the number of scenarios labeled appropriate:  2/10 when rested vs. 4/10 when sleep deprived.  In other words, people with high emotional intelligence have stable, "unwavering" moral judgments, even in the face of sleep loss.  Or, put another way: if you're clear on what you believe, sleep deprivation isn't likely to confuse you.

This is important because the Reuter's title, and indeed the psychiatric utilization of this idea, puts the ability (or inability) to make moral judgments on external factors-- "he was sleep deprived, and that impacts your judgment."   This is prima facie false; but anyway is not supported even by the very science they themselves use to back the claims. 

We can set aside the debate on whether chemicals and psychosis can alter moral judgments; but I think it's fairly safe to say that if your moral judgments are affected by 53 hours of sleep deprivation, sleep isn't the problem.


Note: the study also found that caffeine did not reverse the alterations in moral judgments due to sleep loss.  I don't buy it; more later.