Detection of deception on the Schedule for Nonadaptive and Adaptive Personality: validation of the validity scales

This study used a simulation design to investigate the validity scales of the Schedule for Nonadaptive and Adaptive Personality (SNAP). Undergraduates (N=192) were randomly assigned to two positive distortion (PD) groups, two negative distortion (ND) groups, and a control group. Controls responded normally, whereas the deception groups responded according to assigned characters. Preliminary analyses indicated no significant differences within distortion valence; thus, the groups were collapsed into single PD (n=76), ND (n=79), and control groups (n=37). Mean-level analyses revealed that, consistent with previous studies, ND profiles are easier to detect than PD profiles. Cutoff scores were suggested, and the classification accuracy of these scores converged with the results of several discriminant function analyses to indicate that Rare Virtues and Deviance predict group membership at least as well as MMPI-2 validity scales. Structural analyses revealed that two moderately correlated factors-positive distortion and negative distortion-underlie scores on these validity scales.