Low, Y.L. and Senior, G., University of Southern Queensland, Australia
The Minnesota Multiphasic Personality Inventory (MMPI-2) is the most widely used personality inventory in the world, but little to no research has been conducted on its appropriateness for use in Singapore. The greatest concern regarding base rate differences between Singaporean's and American's endorsement of MMPI-2 items is that systematic over- or under- identification of psychopathology may result. The current study explored the applicability of the U.S. MMPI-2 restandardisation sample in Singapore by examining both normative (106 participants - 62 males, 44 females) and clinical (85 mixed psychiatric cases - 64 males, 21 females) samples. Three levels of analysis were performed comparing Singaporean and U.S. data: examination of item endorsement frequencies; scale and subscale analyses using independent samples t-tests; and the frequencies with which normal and clinical cases in Singapore would elevate (T >5) MMPI-2 scales when either U.S. or Singaporean norms were used. The findings revealed consistent and substantial differences between Singaporean and U.S. samples. Singaporeans had significantly different rates of endorsement for approximately 1 in 5 MMPI-2 items, which impacted directly on more than 70% of the MMPI-2 scales and subscales evaluated. The nett result of these differences was to substantially increase the likelihood of inappropriately identifying normal Singaporeans with no history of psychiatric or neurologic illness as having clinically meaningful levels of psychological distress and disturbance. Similarly analysis of Singaporean clinical protocols revealed a substantial increase in the proportion of cases that elevated MMPI-2 scales when U.S. norms were used rather than Singaporean. These findings suggest that it would be highly likely that some, if not all of the Singaporean MMPI-2 profiles in Singapore will be misinterpreted or over-identified as endorsing psychopathology.