Nikos L. D. Chatzisarantis

Ego Depletion and the Strength Model of Self-Control: A Meta-Analysis

According to the strength model, self-control is a finite resource that determines capacity for effortful control over dominant responses and, once expended, leads to impaired self-control task performance, known as ego depletion. A meta-analysis of 83 studies tested the effect of ego depletion on task performance and related outcomes, alternative explanations and moderators of the effect, and additional strength model hypotheses. Results revealed a significant effect of ego depletion on self-control task performance. Significant effect sizes were found for ego depletion on effort, perceived difficulty, negative affect, subjective fatigue, and blood glucose levels. Small, nonsignificant effects were found for positive affect and self-efficacy. Moderator analyses indicated minimal variation in the effect across sphere of depleting and dependent task, frequently used depleting and dependent tasks, presentation of tasks as single or separate experiments, type of dependent measure and control condition task, and source laboratory. The effect size was moderated by depleting task duration, task presentation by the same or different experimenters, intertask interim period, dependent task complexity, and use of dependent tasks in the choice and volition and cognitive spheres. Motivational incentives, training on self-control tasks, and glucose supplementation promoted better self-control in ego-depleted samples. Expecting further acts of self-control exacerbated the effect. Findings provide preliminary support for the ego-depletion effect and strength model hypotheses. Support for motivation and fatigue as alternative explanations for ego depletion indicate a need to integrate the strength model with other theories. Findings provide impetus for future investigation testing additional hypotheses and mechanisms of the ego-depletion effect.

Integrating the theory of planned behaviour and self-determination theory in health behaviour: A meta-analysis

PURPOSE A meta-analysis of studies integrating the theory of planned behaviour (TPB) and self-determination theory (SDT) in health contexts is presented. The analysis aimed to provide cumulative empirical support for a motivational sequence in which self-determined motivation from SDT predicts the proximal predictors of intentions and behaviour from the TPB. METHODS A literature search identified 36 integrated studies providing 45 tests of effects between TPB and SDT variables. Hunter and Schmidts (1994) methods of meta-analysis were used to correct the effect sizes across the studies for statistical artifacts. Age (old versus young), publication status (published versus unpublished), study design (correlational versus experimental/intervention), and behaviour type (physical activity versus other health-related behaviours) were evaluated as moderators of the effects. A path-analysis using the meta-analytically derived correlations was conducted to examine the proposed motivational sequence. RESULTS Statistically significant corrected correlations were evident among the perceived autonomy support and self-determined motivation constructs from SDT and the attitude, subjective norms, perceived behavioural control, intention, and health-related behaviour constructs from the TPB. Only six of the 28 effect sizes were moderated by the proposed moderators. Path analysis revealed that the significant effects of self-determined motivation on intentions and behaviour were partially mediated by the proximal predictors from the TPB. CONCLUSIONS Evidence from this synthesis supported the theoretical integration and proposed motivational sequence. Results are discussed with reference to the complementary aspects of the TPB and SDT and the need for integrated experimental or intervention studies on a broader range of health behaviours.

The influence of autonomous and controlling motives on physical activity intentions within the Theory of Planned Behaviour

OBJECTIVES: This study aimed to examine how general motives from self-determination theory (SDT; Deci & Ryan, 1985) influence intentions to engage in physical activity within the Theory of Planned Behaviour (TPB; Ajzen, 1985). It was hypothesized that the general motives will influence intentions only when mediated by the specific cognitions of attitude, subjective norms and perceived behavioural control (PBC) from the TPB. DESIGN: A cross-sectional study assessing psychological variables from two theoretical perspectives. METHOD: Self-report questionnaires were administered to 1088 children aged 12-14 years. The childrens intentions, attitudes, subjective norms and PBC towards participating in physical activity were assessed using a TPB questionnaire. A modified verson of Ryan and Connells (1989) perceived locus of causality (PLOC) inventory was used to measure controlling and autonomous motives for participating in physical activity. RESULTS: These data were analysed using structural equation modelling. The resulting well-fitting model demonstrated that attitude and PBC mediated the influence of autonomous motives to perform physical activity on physical activity intentions. The presence of autonomous motives resulted in the effects of the controlling motives being attenuated to zero. CONCLUSIONS: The present results indicate that general autonomous motives to participate in physical activity act as sources of information when childen make their judgments regarding their specific attitudes and PBC. Attitudes and PBC are necessary to translate these general motives from SDT into intentions in the TPB. In terms of targets for intervention, practitioners may positively influence intentions by providing a choice of physical activities to foster increased autonomy in children.

A Multilab Preregistered Replication of the Ego-Depletion Effect

Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental paradigm, in which people completing an initial self-control task have reduced self-control capacity and poorer performance on a subsequent task, a state known as ego depletion. Although a meta-analysis of ego-depletion experiments found a medium-sized effect, subsequent meta-analyses have questioned the size and existence of the effect and identified instances of possible bias. The analyses served as a catalyst for the current Registered Replication Report of the ego-depletion effect. Multiple laboratories (k = 23, total N = 2,141) conducted replications of a standardized ego-depletion protocol based on a sequential-task paradigm by Sripada et al. Meta-analysis of the studies revealed that the size of the ego-depletion effect was small with 95% confidence intervals (CIs) that encompassed zero (d = 0.04, 95% CI [−0.07, 0.15]. We discuss implications of the findings for the ego-depletion effect and the resource depletion model of self-control.

Teacher, peer and parent autonomy support in physical education and leisure-time physical activity: A trans-contextual model of motivation in four nations

An extended trans-contextual model of motivation for health-related physical activity was tested in samples from four nations. The model proposes a motivational sequence in which perceived autonomy support from teachers in a physical education (PE) context and from peers and parents in a leisure-time physical activity context predict autonomous motivation, intentions and physical activity behaviour in a leisure-time context. A three-wave prospective correlational design was employed. High-school pupils from Britain, Estonia, Finland and Hungary completed measures of perceived autonomy support from PE teachers, autonomous motivation in both contexts, perceived autonomy support from peers and parents, attitudes, subjective norms, perceived behavioural control and intentions from the Theory of Planned Behaviour (TPB), and measures of behaviour and past behaviour in a leisure-time context. Path-analyses controlling for past behaviour supported trans-contextual model hypotheses across all samples. Effects of perceived autonomy support from peers and parents on leisure-time autonomous motivation were small and inconsistent, while effects on TPB variables were stronger. There was a unique effect of perceived autonomy support from PE teachers on leisure-time autonomous motivation. Findings support the model, which provides an explanation of the processes by which perceived autonomy support from different sources affects health-related physical activity motivation across these contexts.

Mindfulness and the Intention-Behavior Relationship Within the Theory of Planned Behavior

The present study examined moderating effects of mindfulness on the intention-behavior relationship within the theory of planned behavior. Mindfulness describes a quality of consciousness characterized by heightened clarity and awareness of present experiences and functioning. Study 1 showed that mindfulness moderated the intention-behavior relationship in a leisure-time physical activity context such that intentions predicted physical activity among mindful individuals and not among less-mindful individuals. Study 2 measured counterintentional habits relating to binge-drinking and found that habitual binge-drinking obstructed the enactment of physical activity intentions among individuals acting less mindfully but not among individuals acting mindfully. Finally, Studies 1 and 2 demonstrated that the effects of mindfulness on physical activity were independent of effects observed for habit and variables contained in the theory of planned behavior. These findings suggest that mindfulness is a useful construct that helps understand the intention-behavior relationship within the theory of planned behavior.

Self-determination Theory and the psychology of exercise

The purpose of the Self-determination Theory is to explain motivation and behaviour based on individual differences in motivational orientations, contextual influences, and interpersonal perceptions. The theory has shown utility in explaining the antecedents and processes that underpin exercise behaviour. This review will provide an overview of the theory and its application in explaining health-related exercise motivation, behaviour, and outcomes. Recent innovative research using the theory in exercise contexts will also be reviewed in two key areas: advances in measurement and theoretical integration. Based on this evidence, recommendations for future investigations will be made advocating the development instruments to measure self-determined motivation from first principles, the adoption of experimental and intervention designs to better infer causal links between self-determined motivation and behaviour, further investigation of the role of implicit self-determined motivation in predicting behaviour, and the integration of the Self-determination Theory with other theories of motivation, e.g. the Theory of Planned Behaviour and the Achievement Goal Theory, to provide complimentary explanations of self-determined motivation in exercise contexts. Based on the evidence, the Self-determination Theory demonstrates considerable efficacy in explaining exercise motivation and behaviour. Future research should adopt these recommendations to develop the theory further with a view to informing intervention and practice.

The strength model of self-regulation failure and health-related behaviour

Abstract Successful self-regulation is associated with adherence to health-related behaviour in many domains. In contrast, self-regulatory failure is linked to poor adherence and drop-out. This review presents the strength model of self-control as a framework to explain self-regulation in health-related behaviour contexts. In the model, self-regulation is conceptualised as a limited resource that once depleted results in reduced capacity to further regulate the self. We provide an overview of the hypotheses of the strength model and review research applying the model to self-regulation in four health-related behaviour domains: dietary restraint and eating behaviour, alcohol consumption, smoking cessation and physical activity. Based on our review, we recommend practitioners adopt strategies to minimise self-regulatory failure in people engaging in health-related behaviours such as minimising demands on self-control resources in the early stages of uptake and eating regularly to prevent hypoglycaemia. We advocate techniques to improve self-control strength through rest and training on self-control tasks. Suggestions on how these techniques can be integrated into health-related behaviour-change interventions are provided. Recommendations for future research to identify the mechanisms underpinning self-control resource depletion, conduct further randomised controlled interventions using the model, and integrate strength model hypotheses into existing models of health-related behaviour are proposed.

The Sweet Taste of Success The Presence of Glucose in the Oral Cavity Moderates the Depletion of Self-Control Resources

According to the resource-depletion model, self-control is a limited resource that is depleted after a period of exertion. Evidence consistent with this model indicates that self-control relies on glucose metabolism and glucose supplementation to depleted individuals replenishes self-control resources. In five experiments, we tested an alternative hypothesis that glucose in the oral cavity counteracts the deleterious effects of self-control depletion. We predicted a glucose mouth rinse, as opposed to an artificially sweetened placebo rinse, would lead to better self-control after depletion. In Studies 1 to 3, participants engaging in a depleting task performed significantly better on a subsequent self-control task after receiving a glucose mouth rinse, as opposed to participants rinsing with a placebo. Studies 4 and 5 replicated these findings and demonstrated that the glucose mouth rinse had no effect on self-control in nondepleted participants. Results are consistent with a neural rather than metabolic mechanism for the effect of glucose supplementation on self-control.

Self-regulation and self-control in exercise: the strength-energy model

Self-regulation is an important component of psychosocial theories of exercise behaviour and lack of self-regulatory skills are associated with low adherence to health-related exercise. This review presents a strength-energy model of self-control as an explanation of self-regulation in exercise contexts. The review will provide impetus for original research aimed at understanding exercise behaviour and help develop recommendations for exercise promotion. In the model, self-control is conceptualized as a global but limited resource. Engaging in actions requiring self-control depletes resources leading to self-regulatory failure. Self-control resource depletion is reduced through rest and frequent training on self-control. The expectation of the need to exert self-control in future leads to a conservation of self-control resources. Proposed mechanisms for self-control resource depletion include changes in physiological markers and blood glucose levels. Based on our review, we propose an integrated model of self-regulation incorporating hypotheses from the strength-energy model with those from traditional psychosocial models of exercise behaviour. Recommendations for future research include incorporating hypotheses from the strength-energy model into theories of self-presentation and interpersonal relations in exercise. Practical recommendations aimed at minimising self-control depletion in exercise include the provision of advice on nutrition and recovery, self-control training, and motivational and implementation intention strategies.