The relationship among Neuroticism, Extraversion, intelligence and mechanical reasoning was studied. A sample of 79 male and female postgraduate students were tested on EPI, SPM and Mechanical Reasoning test of DAT. A significantly positive association was obtained between SPM scores and MR right responses and negative with wrong responses. Neuroticism yielded negative association with SPM scores, but with MR the results were insignificant though negative. The Extraversion dimension did not seem to have any relationship with either SPM or 1lZR. An interesting result was the negatively significant correlation between lie score and Neuroticism. It was felt that the lie items were taken to be more of socially desirable values than lies.