The role of degree of intention formation in the relationships between intentions, habits and behaviour

Abstract

We explored the extent to which degree of intention formation moderated intention-behaviour and habits-behaviour relationships in two studies. In study 1 we tested these effects using data from a longitudinal study of 6 health behaviours (N = 865). Degree of intention formation was operationalized as the z transformed multiple correlation of intentions with attitude, subjective norms and perceived behavioural control across behaviours with an individual. Multi-level modelling of 5190 observations revealed reliable cross-level interactions between degree of intention formation and both intention and either a frequency or frequency x stability index of habit. Simple slopes analyses indicated that well-formed compared to poorly formed intentions were associated with stronger intention-behaviour and weaker habit-behaviour relationships. Study 2 replicated these findings with a frequency measure of habit in a longitudinal study of 20 health behaviours (N = 387) again using multi-level modelling (5858 observations). Study 2 also showed these effects of degree of intention formation were mediated by intention stability. These findings would suggest that future research on behavioural prediction should consider not only the strength of people’s intentions to act, but also how well formed are the intentions.