MAXIMIZING INTERNAL AND EXTERNAL VALIDITY IN MMPI MALINGERING RESEARCH - A STUDY OF A MILITARY POPULATION

The authors investigated the effectiveness of various commonly used Mi nnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) indices of exaggeration and malingering in detecting suspected m alingering in a military sample of 121 enlisted men. To maximize exter nal validity, only men undergoing psychological evaluation were used a s participants. Forty-one participants were identified as suspected ma lingerers through multiple criteria and were contrasted with schizophr enic-spectrum and clinic outpatient groups. To improve internal validi ty, the 41 suspected malingering participants were asked to retake the test without exaggerating. Results revealed that there were many fals e positives and fewer, but nonetheless many, false negatives with stan dard malingering indices. It appeared that the Gough Dissimulation sca le (Gough, 1947) might hold the most promise as a measure of malingeri ng, but other scales are also useful. Individual comparisons between d ifferent samples and implications for MMPI-2 (Butcher et al., 1989) ar e presented.