Numerous studies have found evidence for the idea of self-control as a limited resource — that is, a characteristic that can be depleted — but emerging research suggests that this model may not tell the whole story.
Four essential mechanisms are believed to influence self-control: metabolic, cognitive, motivational and affective.
One new theme suggests an energy model of self-control. We usually think of a sugary treat as something that taxes our self-control because we have to expend effort trying to resist it. But what if sweets could actually help to boost self-control?
According to the energy model, self-control relies on carbohydrate metabolism; we deplete our carbohydrate stores as we exert self-control, making it more difficult to exert self-control until the stores are built up again.
Psychological scientist Dr. Daniel Molden and his colleagues decided to test the energy model in a series of four experiments in which participants’ baseline glucose levels were assessed prior to performing tasks that required self-control. They found no evidence for a relationship between self-control and glucose metabolism.
Follow-up studies indicated that participants who rinsed their mouths with a carbohydrate solution showed improved self-control, despite the fact that they didn’t ingest the solution and there was no observable change in their blood glucose levels.
These findings suggest a motivational as opposed to metabolic mechanism for self-control. This research is presented in the journal Psychological Science.
In another article, psychological scientist Dr. Matthew Sanders and colleagues performed a similar study to clarify whether metabolic or motivational mechanisms underlie self-control. The researchers asked participants to engage in a task that required self-control; the participants then rinsed their mouths with either glucose or a non-glucose sweetener while they performed a second self-control task.
The results of the study conceptually replicate those reported by Molden and colleagues. Participants who rinsed with the glucose sweetener demonstrated better self-control than those who rinsed with a non-glucose sweetener, despite the fact that there was not enough time for the glucose to actually be metabolized.
These results, also found in Psychological Science, provide additional evidence to suggest that glucose influences self-control through a non-metabolic route.
The researchers speculate that glucose may activate brain areas involved in selecting and inhibiting action, as well as detecting errors and evaluating competing responses.
The next study challenges the belief that self-control is a limited resource that can be depleted. In this study, psychologists Drs. Michael Inzlicht and Brandon J. Schmeichel reviewed the existing research on self-control and propose an alternative model of self-control focused on process.
This process model holds that our initial exertions of willpower shift our motivation from control and toward gratification. As a part of this process, our attention shifts away from cues that signal the need for control and toward cues that signal indulgence.
Inzlicht and Schmeichel argue that the process model provides a starting point for understanding self-control and that more research examining these cognitive, motivational, and affective influences on self-control is needed. The study can be found in the journal Perspectives on Psychological Science.