People Beliefs about Self-control: Moving Beyond the Limited Resources Model

The limited resources theory became the prevailing theory in explaining the instances of self-control failure, where the momentary inability to control oneself was termed ego depletion. This thesis originally sought to investigate the neural correlates of ego depletion while manipulating participants’ beliefs about self-control within the mindset theory of willpower. For this purpose, ego depletion had to be replicated first using the consecutive tasks paradigm. Stroop task preceded by the food cues task, where hungry participants were required to spot the differences between two flipped pictures at the top and the bottom of the screen while avoiding looking at a highly tempting food picture situated in the middle. the critical aspects of both tasks were piloted by using eye-tracking and pictures piloting to ensure a high practice of self-control. Nevertheless, neither ego depletion, nor the effect of belief manipulation was replicated.

Next, the thesis investigated whether self-control can be approached away from the limited resources theory. To this end, a belief-based model was theorised based on the alternative explanation to ego depletion that was offered by Baumeister et al. (1998). Through exploratory factorial analysis, a model was created where self-control could be implicitly believed as either: energy, skill or knowledge. The model was validated in two replications using confirmatory factor analysis. Through three studies (two studies in chapter 4, and the first study of chapter 5), the model was found significantly correlating with other reported measures of self-control. Through chapter 5, the model predictability of the behavioural variables was found, if present, very weak.

The following conclusions were reached by the thesis: 1) ego depletion was found hard for replication, 2) the three-belief model of self-control was found significantly predicting other reported measures of self-control; namely, the Brief Self-control Scale, the Short Grit Scale, and the implicit beliefs scale of willpower, whereas the model was not able to meaningfully predict the behavioural outcome of the used self-control tasks; namely the food-cues task, Stroop task, and the e-crossing task. 3) Within the three-belief model, beliefs were not equal in their affinity to predict the other self-control measures as the energy belief was found superior to the other beliefs. The implications of these findings and the future directions were discussed in the final chapter.