Main Article Content
Inflexibility of happiness scale, well-being, reliability, validity, Turkish adaptation
The purpose of this study was to evaluate the factor structure, measurement invariance, criterion-related validity, and incremental validity of the Inflexibility of Happiness Scale (IHS) in a sample of 432 undergraduate students from Turkey. To test the factor structure, the sample was split into two subsamples. Exploratory factor analysis (EFA) was conducted in the first subsample and confirmatory factor analysis (CFA) was next conducted in the second subsample. The results of EFA and CFA yielded a single factor structure and measurement invariance across gender was successfully established. In terms of reliability, internal consistency reliability was satisfactory for the IHS. Evidence of criterion-related validity showed that the IHS was positively related to the externality of happiness and negative affect and was negatively related to personality traits and dimensions of psychological well-being. Concerning incremental validity, the results indicated that inflexibility of happiness accounted for a significant amount of variance in predicting domains of psychological wellbeing - purpose in life, personal growth and positive relations over and above the personality traits. Collectively, these results suggest that the IHS is a reliable and valid instrument to measure the inflexibility of happiness beliefs among undergraduate students from Turkey.