Abstract

Youth with intellectual disabilities (ID) are known to present a higher risk for a variety of psychosocial adjustment difficulties. Furthermore, whereas these youth tend to depend on adult caregivers to a greater extent than their typically developing peers, thus making them more likely to potentially benefit from positive relationships with them. Unfortunately, these relationships are all but neglected in research focusing on youth with ID, due to the difficulty of achieving reliable and valid self-report measures with this population, and the limits of informant report in accurately capturing their own perceptions. The goal of the present study was to develop and validate a comprehensive multi-informant (youth, parents, and teachers) measure of relationship quality with parents and teachers specifically developed for your with ID. To do so, this study relies on a sample of Australian (N=253, 67.20% males) and Canadian (N=142, 49.30% males) adolescents with ID (Mage = 15.82). Our results support the reliability, factor validity, discriminant validity (in relation to sex, ID level, country, and comorbidity), convergent validity (with measures of anxiety, depression, externalizing behaviors, and prosocial behaviors reported by youth, their parents, and their teachers), and test-retest stability of this comprehensive measure of relational warm and conflict. The results further support the idea that youth self-reports provide a distinct perspective on relationship quality relative to parents’ or teachers’ reports, and demonstrate that parents and teachers themselves are unable to differentiate their own perspective on these relationships from that of the target youth. Furthermore, the results also suggest a risk of differential item functioning related to teachers’ report of relational warmth in relation to youth with ID presenting comorbid conditions. This measure is likely to help fill an important gap in the literature on relationship quality for youth with ID, and to allow for a much improved assessment process among this population.