Evaluation of the Psychometric Properties of the Scale of Satisfaction of Basic Psychological needs in General with Spanish Adults

The postulates of self-determination theory advocate the satisfaction of basic psychological needs (autonomy, competence and relatedness) to achieve more positive motivation and well-being. The Basic Needs Satisfaction in General Scale (BNSG-S) was created to measure the satisfaction of these needs in life. Its psychometric properties have recently been analyzed, although only with samples of college students. The purpose of the present study was to analyze the validity and reliability of the BNSG-S with a sample of Spanish adults. Three hundred ninety-nine people (202 men and 197 women), aged between 18 and 65, participated in this study. The results of confirmatory factor analysis support the validity of a reduced model of 16 items and a negative-worded method effect. The factor structure was invariant across gender and age. It was also obtained acceptable values of reliability and temporal stability. The analysis of external validity evidences showed that the satisfaction of the three basic psychological needs was positively associated with self-determined motivation towards physical activity and satisfaction with life. These results support the utilization of the instrument in the Spanish context.