Modelling the influence of automaticity of behaviour on physical activity motivation, intention and actual behaviour

In research and in practise social-cognitive models, such as the theory of planned behaviour (TPB), are used to predict physical activity behaviour. These models mainly focus on reflective cognitive processes. As a reflective process, intention is thought to be the most proximal predictor to behaviour. Nevertheless, research suggests that the relation between intention and actual behaviour, the so called intention-behaviour gap, is moderate. Many health-related actions in daily life are performed repetitively and with minimal forethought. In contrast to social-cognitive theories, dual-process theories suggest that behaviour is based on both reflective and automatic processes. Recent research reveals that automatic processes, such as habit, can significantly explain physical activity behaviour initiation. One important finding was that automaticity of behaviour strengthens intrinsic motivation for physical activity. However, research has yet to explain the effects of automaticity of behaviour within the adolescent population, although lifestyle habits are strongly influenced during this period of the lifespan. The purpose of this study was to explore the role of automaticity of behaviour within the constructs of the theory of planned behaviour (TPB) and the self-determination theory (SDT), using the integrated model of SDT and TPB. A sample of 582 highly active adolescents aged 15-19 completed measures of behaviour regulation, attitude, intention, physical activity behaviour and automaticity of behaviour. Results show that automaticity of behaviour correlated with higher forms of self-determined behaviour. Two multiple regression analysis were conducted to explore the effects of automaticity of behaviour on both intentions and on actual physical activity behaviour. Results show that automaticity of behaviour is a significant explanatory factor for physical activity behaviour (β= .10, p=.01), even if controlled for reflective processes. Moreover, automaticity of behaviour was the second strongest explanatory factor for intentions (β= .14, p=.00). Secondly, a difference in behaviour regulation was found between the models on intention and physical activity. Intentions were best explained by intrinsic motivation (β= .18, p=.00), followed by automaticity (β= .14, p=.00) and attitudes (β= .13, p=.01). Actual physical activity behaviour was best explained by integrated behaviour regulation (β= .24, p=.00), attitudes and intention, while intrinsic motivation had no significant explanatory power on actual physical activity behaviour. The present findings support previous research, which suggests that automaticity of behaviour has a role in the explanation of physical activity behaviour. The discrepancy in behaviour regulation between intentions and actual physical activity behaviour is further discussed, as well the effects of automaticity on behaviour regulation, attitudes and intention. Finally, directions for future research and practical implications are presented.