Direct and moderation effects of swimming competence using an integrated model of self-determination theory (SDT) and theory of planned behaviour (TPB) were examined in two large-scale studies among young children. Specifically, we examined whether swimming competence had direct and moderation effects on social psychological variables of perceived need support, autonomous motivation, TPB social cognition constructs, and intention. In Study 1, using a cross-sectional survey of 4959 primary school children, swimming competence formed significant positive relationships with all model variables (β =.061 to.330, p < .05) except intention (β = -.009, p > .05), and its moderation effect on model parameters were small in size or not statistically significant. In Study 2, using a pre-post-test quasi-experiment among 1,609 primary school children, improvement of swimming competence was associated with change-scores in all model variables (β =.046 to.230, p < .05) except subjective norm (β =.049, p > .05). Swimming competence did not significantly moderate the parameter estimates of the integrated model (p > .05) at the change-score level. Findings indicate that swimming competence is associated with higher autonomous motivation; TPB social cognitions of attitude, subjective norm, and perceived behavioural control; and intention. However, swimming competence did not moderate the parameter estimates of the integrated model.
Keywords: Swimming ability; self-determined motivation; self-efficacy; social cognition; theoretical integration; theory of planned behaviour.