Our self-control may not be a finite resource that diminishes throughout the day, but we may still experience fatigue while persisting in a single task, according to a study published in the open-access journal PLOS ONE by Daniel Randles from the the University of Toronto, Canada and colleagues.
Previous studies have suggested that we have a finite resource of self-control, and thus have theorized that our motivation for cognitively challenging activities will deplete throughout the day. However, recent attempts to demonstrate people losing motivation on tasks throughout an entire day have failed to yield sufficient evidence to support this theory.
To investigate whether we have a finite amount of self-control, Randles and colleagues monitored two groups of students (N1 = 8,867, N2 = 8,754) over separate 17-week intervals with 24-hour coverage, as they engaged in voluntary learning and self-testing using an online program.
The researchers found that time of day had very little effect on students' success at completing the tasks, which is contrary to the theory that our self-control depletes throughout the day.
The researchers found that a student could concentrate on a single task for about an hour before their performance depleted on that specific task, which is consistent with previous research, but the time of day at which the task was performed did not affect performance.
In order to access this information, this study did not consider demographics or what the students thought about the task, which the authors suggest would be important details to allow for a more complete interpretation of the results.
However, they maintain that this research casts some serious doubt on the theory that we have a limited reservoir of self-control to draw from throughout the day, and hopefully opens the door for additional studies on motivation.