Classification Discrepancies in Two Intelligence Tests: Forensic Implications for Persons with Developmental Disabilities
Authors:
Cavagnaro, AT; Shuster, S; Colwell, K
Source:
*JOURNAL OF FORENSIC PSYCHOLOGY PRACTICE*, 13 (1):49-67; JAN 1 2013
Abstract:
Accurate measurement of intellectual abilities of adults with
developmental disabilities impacts key legal issues, including
adjudicative competence, civil commitment, and death penalty litigation.
This research compared standardized measures of intelligence in a
multicultural sample of adults with developmental disabilities. Within
subjects ANOVA revealed significantly higher Wechsler Adult Intelligence
Scale-Third Edition IQs compared to Wide Range Intelligence Test (WRIT)
IQs, with a median difference of 13.0 points. Underestimates provided by
the WRIT could lead to adverse legal decisions, including exacerbation
of malingered cognitive dysfunction cases and permitting individuals
guilty of criminal acts to escape sentences. Policy implications exist
for the methodology of intellectual assessment given that instruments
yield discrepancies. We suggest utilizing standardized measures with
strong psychometric integrity in Atkins hearings and incorporating
relevant collateral information when generating clinical case
formulations. This will give clinicians additional relevant data and
afford greater precision in forming clinical judgments regarding
diagnosis and cognitive level in forensic cases.
