The Social Aptitudes Scale: looking at both "ends" of the social functioning dimension.

PURPOSE: Dimensional approaches are likely to advance understanding of human behaviors and emotions. Nevertheless, it is unclear whether instruments in psychiatry capture variability at the full spectrum of these dimensions. We aimed to investigate this issue for two scales assessing distinct aspects of social functioning: the Social Aptitudes Scale (SAS), a "bidirectional" scale constructed to investigate both "ends" of social functioning; and the social Child Behavior Checklist (CBCL-social), a "unidirectional" scale constructed to assess social problems. METHODS: We investigated 2512 children and adolescents aged 6-14. Item response theory was used to investigate on which range of the trait each scale captures information. We performed quantile regressions to investigate if correlations between SAS and CBCL-social vary within different levels of social aptitudes dimension and multiple logistic regressions to investigate associations with negative and positive clinical outcomes. RESULTS: SAS was able to provide information on the full range of social aptitudes, whereas CBCL-social provided information on subjects with high levels of social problems. Quantile regressions showed SAS and CBCL-social have higher correlations for subjects with low social aptitudes and non-significant correlations for subjects with high social aptitudes. Multiple logistic regressions showed that SAS was able to provide independent clinical predictions even after adjusting for CBCL-social scores. CONCLUSIONS: Our results provide further validity to SAS and exemplify the potential of "bidirectional" scales to dimensional assessment, allowing a better understanding of variations that occur in the population and providing information for children with typical and atypical development.