Measuring beliefs about the malleability of mindfulness skills: Validation of the Turkish version of the mindfulness mindset scale

A B S T R A C THeterogeneity in the effects of mindfulness-based interventions points to the potential role of individual belief structures in shaping intervention outcomes. One candidate construct is beliefs about the trainability of mindfulness skills. The present study adapted the Mindfulness Mindset Scale (MMS) into Turkish and evaluated its psychometric properties in a sample of 532 university students using complementary Classical Test Theory and Item Response Theory approaches. Confirmatory factor analysis supported a unidimensional structure and indicated adequate internal consistency (ρ = .78). Item-level IRT analyses yielded distinct discrimination and threshold parameters, with the test information function indicating the highest precision at moderate levels of the latent trait. Multigroup CFA supported scalar measurement invariance across gender, and differential item functioning analyses indicated no evidence of item bias. For convergent and discriminant validity, the scale showed negligible associations with trait mindfulness and generalized distress, whereas a positive moderate association with a fixed creativity mindset supported the cross-domain consistency of fixed implicit beliefs. Overall, the findings support the Turkish MMS as a psychometrically sound instrument for assessing beliefs about the trainability of mindfulness skills and extend the cross-cultural evidence base for the scale.