Donald Trump takes a lot of risks.
He antagonizes his fellow Republicans in Congress, putting his legislative agenda into jeopardy. He has threatened a government shutdown, betting he won't get blamed if it occurs. And he continually tweets the first thing that pops into his head, apparently unconcerned by how these often-caustic messages are interpreted by friend or foe.
The common explanation for this is that the president lacks "impulse control." But the problem may be simpler: What if he isn't getting enough sleep?
In a small-scale new study, Swiss researchers report that, after a week of restricted sleep (five hours per night), men were more likely to take risks. Furthermore, they were not consciously aware of this change in their behavior.
Brain-activity monitoring suggests this is due, at least in part, to "the right prefrontal cortex not being able to recover properly due to chronic lack of sleep," reports researcher Christian Baumann of University Hospital Zurich.
"All of us, but particularly leaders of companies and countries, are well-advised to work and make decisions only when fully sleep-satiated."
The study, published in the Annals of Neurology, featured 12 men between the ages of 18 and 28. All reported they normally slept seven to eight hours per night. They were tested under three conditions: After a normal night's sleep; after a period of sleep deprivation (40 hours of continual wakefulness); and during a seven-day period in which they slept five hours per night.
The latter protocol was performed, in part, at a sleep lab. That way, the limitation could be enforced, and researchers could use equipment to measure electrical activity in the participants' brains.
Twice a day, the young men engaged in a risk-taking exercise that is commonly used in behavioral economics experiments. In a series of trials, they were forced to choose between receiving a specified amount of money, or taking a chance on getting a larger sum.
The probability of receiving the larger amount ranged from 20 percent to 80 percent. After making a series of such choices, participants were asked to evaluate their behavior on a scale form "never risky" to "always risky."
Baumann and his colleagues report men whose sleep was curtailed night after night tended to engage in riskier behavior. Importantly, this effect was not found after the single night of sleep deprivation, but rather was the result of chronic insufficient shut-eye.
"Compared to regular sleep, the clear majority of subjects—11 out of 14—showed an increase in risk-seeking after (a week-long) sleep restriction," the researchers write. "Six of them changed from being risk-aversive after regular sleep to being risk-seeking after sleep restriction."
Even more troubling, "the increase in risk-seeking was subjectively not noticed," they add. Given that "30 percent or more of the population of various countries report inadequate sleep deprivations," this lack of awareness could have widespread consequences for everyone from military officers to Wall Street traders.
The researchers don't mention any particular sleep-deprived decision-makers by name, but it's easy to detect a reference to the current American president in their concluding statement: "Our results suggest that all of us, but particularly leaders of companies and countries, are well-advised to work and make decisions only when fully sleep-satiated."
If Trump would heed that call, we'd all sleep better.