Sleepiness and Behavioral Risk-Taking: Do Sleepy People Take More or Less Risk?

Although sleep loss has been implicated in risk-taking behavior, it is unclear how individuals' current propensity to fall asleep, known as sleepiness, influences risk-taking. Because sleepiness is not only driven by recent sleep but also by factors such as circadian rhythm and current stimulation, it may be an important contributor to risk-taking as it reflects the more immediate sleep-wake state.

One hundred thirty participants were recruited from a large Midwestern U.S. university.

Participants completed a short personality survey, reported their current sleepiness on the Stanford Sleepiness Scale, and then completed the Balloon Analog Risk Task, a computerized risk-taking measure in which participants earned real money for their performance.

There was little support for a linear relation between sleepiness and risk-taking, but the evidence indicated a robust curvilinear relation. Even after controlling for important individual differences in sleep and risk-taking, participants who were moderately sleepy took longer to complete the risk-taking task, pumped balloons more, and exploded more balloons than those who were either low or high on sleepiness.

The curvilinear relation between sleepiness and risk-taking sheds light on inconsistencies in prior findings linking sleepiness and sleep loss to risk-taking behavior. Moreover, current sleepiness appears to have unique implications for risk-taking.