DETECTION OF SIMULATION ON THE MPI BY SUBJECTS GIVEN THE RATIONALE OF THE LIE SCALE

The MPI was administered to independent groups of 34 subjects under four sets of instructions. Group C was given the standard instructions, group FSI was asked to simulate a ‘desirable’ personality and told the rationale of the lie scale, group FSIE was given the FSI instructions plus examples of lie scale items and group FSIP was asked to simulate and was given a previously established ‘popular’ version of the rationale of lie scales. The three experimental groups presented themselves as ‘desirable’. Group FSI evaded detection by the lie scale most effectively, obtaining a mean score similar to that of group C. Groups FSIE and FSIP obtained similar and significantly higher scores on the lie scale, but 50 per cent of the subjects evaded detection. It was concluded that a fresh approach to detection of simulation on questionnaires is needed.