SELF-CONTROL AND HEALTH BEHAVIOUR CHANGE: A NEW BEHAVIOURAL ECONOMICS MODEL INCORPORATING COGNITIVE EFFORT

Purpose:

   Self-control, to reject immediate pleasures in favour of longer-term benefits, is critical for health behaviour change, as evident from everyday life and several studies (e.g. on diet, physical activity or smoking cessation). Behavioural economics theories are useful for exploring decision making in health domain. However, existing models of self-control (with their abstract axioms and mechanisms, e.g. a game in human mind between a sequence of impulsive selves and a long-run self) require complex analyses and extensions to explain empirical findings on health behaviour change. Recently, the role for cognitive effort in self-control of impulses has been shown in neuroscience and psychology. In this study, a behavioural economics model of self-control that incorporates cognitive effort is proposed to explain observed factors of health behaviour change.

Method(s):

   Link between self-control and registration of cognitive effort was established in neuroimaging studies: for displayed self-control, functional magnetic resonance revealed activation in dorsolateral prefrontal cortex, reduced for impulsive choices. Behavioural experiments showed that self-control failure comes from unfavourable comparison of cognitive effort cost and self-control benefits. Based on the above evidence, a model incorporating cognitive effort that shapes self-control of impulses is developed. The key model assumptions, (1) effort, improving cognition of self-control benefits, is exerted to minimize regret from self-control of impulses, (2) regret combined with effort cost (less favourable cost-benefit comparison) increases self-control failure risk, are supported by neuroscientific evidence and psychological studies. Incorporating perceived health benefits of self-control and impulsive rewards of unhealthy behaviour in the model, the role for cognitive effort in health behaviour change is explored.

Result(s):

   The following empirical findings are explained by the model: negative impact of cognitive load on sticking to diet; low discount rate (patience) and positive response to behaviour-change interventions; impatience and the relapse of unhealthy behaviour; risk aversion and smoking cessation success; impulsivity and smoking relapse; U-shaped relationship between adherence to lifestyle-change recommendations and age. The model predicts that, for large impulsive rewards, self-control failure is less likely for ‘stopping’ unhealthy behaviour, compared to ‘avoiding’ the relapse of this behaviour, and that cognitive effort avoidance inhibits health behaviour change.

Conclusion(s):

   A new model accounting for the role of cognitive effort in self-control provides promising behavioural economics tools to explore the factors facilitating health behaviour change and its maintenance.