Evaluating the Credibility of Statements Given by Persons with Intellectual Disability

The objective of this study was to analyze the features that distinguish statements given by actual and simulated victims with mild to moderate intellectual disability, using the credibility analysis procedure known as Reality Monitoring (RM). Two evaluators trained in credibility analysis procedures using content criteria evaluated 13 true statements and 16 false statements. The results obtained show that there is little difference between the two types of statements when analyzed on the basis of content criteria using the RM procedure. The only criteria that proved to be significant for discriminating between the two types of statements were the amount of details and the length of spontaneous statements obtained through free recall. None of the phenomenological characteristics studied turned out to be significant for discriminating between actual and simulated victims. Graphic representation using high-dimensional visualization (HDV) with all criteria taken into consideration shows that the two types of statements are quite heterogeneous. Cluster analysis can group cases with a 68.75% chance of accuracy.