The differentiation of adaptive behaviours: evidence from high and low performers

Background: Professionals who use measures of adaptive behaviour when working with special populations may assume that adaptive behaviour is a consistent and linear construct at various ability levels and thus believe the construct of adaptive behaviour is the same for high and low performers. That is, highly adaptive people simply are assumed to have a higher level of adaptive behaviour than their less adaptive peers (i.e. individuals with special need, including intellectual disability). This study examines the viability of this assumption and poses an alternative hypothesis: adaptive behaviour is qualitatively different for high and low performers. Methods: Portions of the Adaptive Behaviour Assessment System-II’s standardisation sample were used to examine the structure of adaptive behaviour in high and low performers. Results. Results of factor analysis indicated that the amount of variance attributable to a general factor of adaptive behaviour declines at lower levels of adaptive ability, indicating that adaptive behaviours are not organised in the same manner across the spectrum of adaptive ability. Conclusions: Additionally, knowledge of an individual’s adaptive skills, not merely their general adaptive composite, seemingly is especially important when working with special needs children and youth who display deficits in adaptive behaviour.