Early birds and night owls have different daily habits. But a study suggests that they both share one trait: As the clock ticks, their decisions get dicey.
Neuroscientists examined the quality of moves in more than one million games of chess in an online database. They charted the decisions of 99 prolific players by gauging the time they took for each move and its usefulness in leading to a victory.
As expected, early risers played more games in the morning, whereas night owls were active at dusk and beyond. But both sets of players took longer for each move and made better game choices early in the day and soon after they woke up. Come evening, their game play quickened by 2.5%, while their moves grew less effective by the same margin, on average.
The study revealed a pervasive switch in decision strategy from safe play in the morning to riskier—faster and less successful—moves at sundown. The finding shows that people may have greater control over our decisions earlier in the day and soon after waking, regardless of when one prefers to sleep. As people grow tired, their bodies’ need for sleep could dictate the quality of their choices—no matter how focused we think we might be.