CORRELATIONS BETWEEN ROSCHACH AND WAIS-IV IN SUBJECTS WITH INTELLECTUAL DISABILITY

Background. Wechsler Adult Intelligence Scale – IV (WAIS-IV) and Rorschach Inkblot Test are often included in diagnostic routines by many clinicians in order to measure the “Performance” from two different points of view; while the WAIS-IV is used to analyse intelligence and cognitive abilities, the Rorschach test evaluates how people respond to various standardized tasks. The administration of projective methods in subjects with a diagnosis of intellectual disability presents some issues related to the validity of the test and therefore the reliability of the results. Methods. The sample of this study consisted in 25 records of outpatients with intellectual disability selected from the archives of Policlinico Umberto I Hospital’s clinical psychological assessment service. All the selected records had to contain the full administration of psychological assessment battery which including both the Rorschach test and the WAIS-IV; in addition, all the Rorschach worksheets have been coded using the Comprehensive system of J.E Exner. Multiple Spearman’s rank correlations were performed to determine whether there were significant association between WAIS-IV and Rorschach indexes. Furthermore, the total sample was splitted in two subgroups: the first was composed of subjects whose IQ scores falls in the WAIS-IV range of <69 points (N=19), while the second one was composed by those whose IQ scores falls into 70-79 range (N=5). N=1 case has been excluded because the subject wasn’t part of neither of the previous ranges of IQ. In order to analyse differences between groups a one-way ANOVA was performed. Results. Rorschach’s Zd index (Z difference) reaches a strong negative correlation with both WAIS-IV Full IQ scale (p=<0.01) and Perceptual Reasoning Index (PRI; p=<0.01), while a moderate negative correlation was found with Working Memory Index (WMI; p=<0.05) and Processing Speed Index (PSI, p=0.05). Another moderate correlation was found between S (White space responses) and PRI (p=<0.05). One-way ANOVA shows that the two subgroups only differ in S responses. Conclusions. These findings suggest that Zd may not just be a factor which describes processing Efficiency, but it could describe a complex factor which also involves cognitive domains associated with Perceptual reasoning assessed within WAIS-IV. Regarding the findings on S responses, results are in line with the international literature.