Beyond Autonomy, Competence, and Relatedness: A Comprehensive Scale for Basic Psychological Needs and Novelty in...

Background/Objectives: Grounded in Self-Determination Theory, this study aimed to translate and validate the Basic Psychological Need Satisfaction and Frustration Scale (BPNSFS), including the Novelty dimension, within the Portuguese exercise context. Given the emerging evidence of novelty as a potential candidate for a basic psychological need, this research examined the psychometric properties and temporal stability. Furthermore, this study explored the nomological validity of these constructs regarding exercise enjoyment and satisfaction with life. Methods: The sample comprised 500 gym-goers (263 females; 237 males), aged between 18 and 65 years (M = 33.76; SD = 12.94). Confirmatory Factor Analysis and Exploratory Structural Equation Modeling were employed to compare the factor structure. Temporal stability was assessed through a test-retest procedure with a four-week interval (n = 50). Results: Exploratory Structural Equation Modeling provided a superior fit to the data (CFI = 0.98; TLI = 0.97; RMSEA = 0.04) compared to Confirmatory factor Analysis, supporting the distinctiveness of the eight dimensions. The instrument demonstrated strong internal consistency (composite reliability ranging from 0.78 to 0.90) and adequate discriminant validity. Path analysis revealed that novelty satisfaction was significantly associated with enjoyment and satisfaction with life. In reverse, novelty frustration was negatively associated with these well-being indicators. Intraclass correlation coefficients (0.75 to 0.83) confirmed robust temporal stability. Conclusions: These findings provide evidence that the Portuguese version of the BPNSFS, including the novelty dimension, is a psychometrically comprehensive instrument for the exercise context. The results support the inclusion of novelty as a relevant psychological need within Self-Determination Theory.