DETECTION OF SIMULANT AND HONEST SUBJECTS THROUGH MMPI-2 SCALES

A great number of research studies have shown that individuals give di shonest responses for various reasons when answering evaluation instru ments. Thus, faking has been the subject of many studies. The objectiv e of the study presented here, one of the first validity studies of th e MMPI-2 in Spanish, was to evaluate which of the scales in the invent ory discriminated a higher percentage of simulating subjects from hone st ones. The sample consisted of 119 psychology students and 90 schizo phrenic psychiatric patients. The revised version of the Minnesota Mul tiphasic Personality Inventory (MMPI-2), containing 567 items translat ed in to Spanish, was used. The students answered the inventory twice. The first time they were given the usual instructions, the second tim e the group was divided into two sections: one section was instructed to simulate a very good psychological adjustment and the other to simu late paranoic schizophrenia. The patients answered the inventory only once. The measures obtained were: means and standard deviations. The d ifferences for validity and clinical scales with the T student test in the following situations were also calculated: 1) For subjects answer ing the inventory under standard instructions and then faking symptoms of paranoid schizophrenia. 2) For subjects answering to the inventory with instructions to fake having paranoid schizophrenia, and for para noid schizophrenic psychiatric patients. 3) For subjects answering the inventory under standard instructions and then faking good psychologi cal adjustment Cut off scores and power prediction levels in order to discriminate between fakers honest and psychiatry patients profiles we re also calculated. T scores and profiles for basic scales for honest students fakers and psychiatric patients were also obtained. The resul ts showed relevant similarities with the data reported in previous stu dies on the same subject. Subjects who faked schizophrenia were easily discriminated from students under standard instructions and psychiatr ic patients. F, F back and F-K, with a probability level of .005, were the best indexes to distinguish between subjects who were faking bad and honest students. It was also observed in this study that giving in formation to the students about a specific mental disorder did not mak e them capable of avoiding the MMPI-2 faking detection. As it has been found in other studies, subjects who were faking good, were more diff icult to discriminate. Therefore, the conclusion is that the MMPI-2 is a highly reliable instrument to correctly discriminate students fakin g paranoic schizophrenia, from honest students, but less reliable to d etect subjects simulating being well adjusted to their situation. In a ddition, important differences in regards to gender were found.