Measuring Growth Mindset: A Validation of a Three-item Scale and a Single-item Scale in Youth and Adults

[See 10.1027/1015-5759/a000735 for published version] A growth mindset is the belief that personal characteristics, specifically intellectual ability, are malleable and can be developed by investing time and effort. In recent decades, numerous studies have investigated the associations between growth mindset and academic achievement, and large intervention programs have been established to train adolescents to develop a stronger growth mindset. However, methodological research on the adequacy of the measures used to assess growth mindset is scarce. In our study, we conducted one of the first comprehensive assessments of the psychometric properties of Dweck’s widely used three-item Growth Mindset Scale in two samples - adolescents (age 14–19 years) and adults (age 20–64 years) - and empirically demonstrate the comparability (i.e., measurement invariance) of the scale across these age groups. Furthermore, we identified and validated a single-item measure to assess growth mindset in research settings with severe time constraints. Our results show that both the short (three-item) and ultra-short (single-item) scales have acceptable psychometric properties in terms of of reliability, comparability, and validity. However, our analyses did not yield support for some of the central tenets of mindset theory, calling for future research on the criterion validity of growth mindset.