Evaluating the dimensionality of Self-Determination Theory’s relative autonomy continuum
We conducted a theoretical and psychometric evaluation of Self-determination theory’s "relative autonomy continuum," an important aspect of the theory whose validity has recently been questioned. We first derived a comprehensive relative autonomy index (C-RAI) containing six subscales and 24 items, by conducting a paired paraphrase content analysis of existing RAI measures. We administered the C-RAI to multiple U.S. and Russian samples, assessing motivation to attend class, study a major, and take responsibility. Item-level and scale-level multi-dimensional scaling analyses, confirmatory factor analyses, and simplex/circumplex modelling analyses re-affirmed the validity of the relative autonomy continuum, across multiple samples, stems, and studies. Validation analyses predicting subjective well-being and trait autonomy from the six separate subscales, in combination with various higher-order composites (weighted and unweighted), showed that an aggregate unweighted RAI score provides the most unbiased and efficient indicator of the overall quality of motivation within the behavioral domain being assessed.