The development and initial validation of the Exercise Causality Orientations Scale.

Deci and Ryan's causality orientations theory suggests that there are individual differences in motivational orientation towards initiating and regulating behaviour. They described three causality orientations: autonomy, control and impersonal. The aim of this paper is to describe the development and concurrent validity of the Exercise Causality Orientations Scale (ECOS), which was designed to measure the strength of these three orientations within exercise. Altogether, 592 working adults aged 35.0 +/- 11.4 years (mean +/- s) completed the ECOS and measures of self-determination, self-consciousness and social desirability. The analysis was conducted in two parts. First, the data were subjected to confirmatory factor analysis using a multi-trait, multi-method framework. The original model resulted in a poor fit to the data. On the basis of its modification indices, three scenarios with ambiguous items were removed successively, resulting in a scale with good psychometric properties. Secondly, Pearson's correlations were conducted between the subscales of the ECOS and those of the questionnaires used for validation. Most of the results supported a priori hypotheses. In conclusion, our results show the ECOS to have good psychometric properties and they provide some support for its concurrent validity.