Psychometric properties of the Basic Psychological Need Satisfaction and Frustration Scale - Intellectual Disability (BPNSFS-ID)

The Basic Psychological Need Satisfaction and Frustration Scale – Intellectual Disability (BPNSFS-ID), an adapted version of the original BPNSFS (Chen, Vansteenkiste, et al., 2015), operationalizes satisfaction and frustration with the three basic psychological needs according to self-determination theory (SDT): autonomy, relatedness, and competence. The current study examined the psychometric properties of the BPNSFS-ID in a group of 186 adults with mild to borderline intellectual disability (MBID). The results indicated an adequate factorial structure of the BPNSFS-ID, comprising the satisfaction and frustration of each of the three needs. The associations between BPNSFS-ID subscales autonomy, relatedness, and competence and the self-determination subscale of the Personal Outcome Scale (POS), the De Jong Gierveld Loneliness Scale, and the General Self-Efficacy Scale – 12 (GSES-12), supported the construct validity. In addition, the BPNSFS-ID demonstrated high internal consistency (α = .92) and 2-week test-retest reliability (r = .81 for the composite subscale autonomy, r = .69 for the composite subscale relatedness, and r = .85 for the composite subscale competence). Overall, the BPNSFS-ID proved to be a valid and reliable measure of basic psychological need satisfaction and need frustration among people with MBID