Sexual abuse victim empowerment programme: An archival study assessing the relationship between adaptive functioning and severity of intellectual disability in a group of intellectually disabled victims of sexual abuse

  • Mario R. Smith


The nosology and the criteria for intellectual disability (mental retardation) have been commonly accepted to include significantly sub average general intellectual functioning (having an IQ of 70 or less) and impairment in adaptive functioning manifested before the age of 18 years. The assessment of intellectual functioning as the primary criterion has been well-documented with the use of individual scales reporting good psychometric properties. However, adaptive functioning has mostly been assessed via clinical interviewing, observation and collateral interviews with significant others. Adaptive capabilities within the intellectually disabled have received less attention. The Vinelands maturity scale, an objective measure of adaptive functioning, has been used widely with good effect in diagnosis. The interaction between the severity of intellectual disability and adaptive functioning has been described for the purposes of categorization. However, attempts at providing empirical support for the differential profile have been lacking.

This article reports on an archival study that aimed to examine the relationship between severity of intellectual disability and adaptive behavior. This study used verbatim protocols that formed part of a psycho-legal assessment in the SAVE programme assisting intellectually disabled victims of sexual abuse. Significant differences in adaptive functioning domains among groups of mild, moderate and severely intellectually disabled participants were tested for empirically.

Null findings were reported for all domains, except socialization, based on chronological age. However, significant differences were reported on all domains when using adaptive functioning scores based on test-age equivalents. In short, chronological age is not useful as a criterion when
assessing adaptive functioning relative to the level of intellectual disability. A differential capability profile relative to the level of intellectual disability was empirically supported using test-age equivalents.

The empirical evidence here can be useful to augment the findings of IQ testing, that can be flawed and subject to extraneous variables, when determining whether a diagnosis of intellectual disability is indicated.


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