The list of physical and mental problems that we know come from sleeping too little is getting longer. A new study suggests another: shorting ourselves on sleep may lead to making riskier decisions. And the insidious part is that we may not even realize we’re doing it.
The study observed a group of participants, ages 18-28, while they slept only 5 hours a night for a week, as compared to another group getting 8 hours a night. Twice a day they were given a decision-making task with two outcomes: either receiving a set amount of money for certain, or gambling for a higher amount and getting nothing if they lost.
The results became more pronounced as the week went on. At the start, less sleep didn’t influence the participants’ decisions, but as the sleep-deprived nights added up, more and more of them took the bigger risk. Eventually almost all of them did.
The researchers were also interested in how the participants perceived their decisions—if they saw them as more risky than they’d otherwise be, given a few more hours of sleep. Most of the participants said they didn’t see any difference. “We therefore do not notice that we are acting riskier when suffering from a lack of sleep," said Christian Baumann, study co-author and professor of neurology.
While occasional risk-taking has its benefits, the results from this study are concerning because the participants' risk-taking seemed to become impulsive, and their awareness about why they were taking more risks was phased out along with their lost hours of sleep.
The study had a few shortcomings worth mentioning. First, it was a small study that serves best as a pilot for future research to replicate. And the participants were all young males, who, some evidence would suggest, are prone to making riskier decisions even under stable conditions. But the way their decision-making changed as the effects of sleeping less took a toll suggests that the results can’t be written off to gender or age.
Sleeping too little is already linked to attention deficits, especially in younger people. In fact, recent research is pointing to a possible reinterpretation of ADHD as a sleep related disorder. Attention and decision-making are abilities that operate from a shared axis in our brains, so it’s no surprise that something affecting one would also affect the other.
The good news is that for most of us this is a problem with a solution, although we’re up against some tough distractions to reach it. A diet of streaming, social media and video games is eating up more of our evening hours, along with the traditional sleep erasers like stress.
But we can choose to put a positive spin on findings like these and use them as incentive to reclaim the nighttime territory we’ve ceded to distractions. The science is clear that the benefits of sleeping a little more are hard to overstate.
The study was published in the journal Annals of Neurology.