Simulated subnormal performance on the Stanford Binet-V: an exploratory investigation of the Stanford Binet rarely missed items index

The purpose of this study was to derive an embedded validity index of effort for the Stanford-Binet Intelligence Scales-Fifth Edition (SB5; Roid, 2003a) and to validate this index using an analog sample of individuals feigning mild mental retardation (MR). Of the data provided by Dr. Roid, 307 healthy individuals aged 18-35 with full scale intelligence quotients (FSIQ) greater than 70 were included in this study (n = 307) as well as 31 individuals with FSIQ scores in the MR range. Also, a sample of 108 undergraduate students at Louisiana State University was asked to participate in this study in exchange for extra credit in an undergraduate psychology class. One group, analog malingerers, was instructed to feign mild MR and respond to the material in a manner consistent with that population while those assigned to the control group were asked to perform to the best of their ability. Frequencies of incorrect responses were calculated for each item and items retained were missed significantly more frequently, p \u3c .001, by individuals asked to feign MR. Twenty-one items were retained and compose the Stanford-Binet, Fifth Edition Rarely Missed Items Index (SBRMI). Logistic regression analyses indicated that the SBRMI was a significant predictor of malingered MR, and ROC curve suggested that a cutoff score of 17.50 yielded a sensitivity of 70.5% and a specificity of 100%. Overall, it appears that the SBRMI is a clinically useful tool for detecting malingered mental retardation