There are a variety of factors that can affect your decision-making. And today I learned that time of day may be one of them. A group of Argentinian researchers decided to study the impact of time of day on decision-making. And they did it in a brilliant way - by examining online chess matches:
The research team, which included postdoctoral fellow María Juliana Leone (who won a Woman International Master chess title in 1999) and APS Fellow Mariano Sigman, found that decision-making abilities do appear to fluctuate across the day: In the morning decisions tend to be slower but more accurate, and late in the day decisions were made more abruptly with less accuracy.
When it comes to our behavior and time of day, individual differences in circadian rhythms, called chronotypes, play a role in when people prefer to go to sleep and when they wake up. Individuals who prefer to stay up late are called “owls” and those who prefer to get up early are called “larks.” Other individuals are somewhere in the middle.
The researchers recruited samples of players who had played at least 2,000 games. Approximately 100 participants were asked to note their Time Zone, age, and to complete a Morningness-Eveningness Questionnaire (MEQ), which indicates morning or evening preferences. The players also completed a short questionnaire about daily sleep routines, meal habits, and wake-up times.
As a control group, the researchers also included games from 14 computers that regularly play in FICS, since “computers are not expected to have diurnal fluctuations in the decision process.”
The results showed that chess playing activity tended to follow along with a player’s chronotype: Larks played more games in the morning and owls played more often in the evening. However, chronotype did not appear to have a significant impact on play performance. Regardless of players’ chronotype, the researchers observed a consistent pattern in decision-making quality and time of day.