Relative predictive power of the optimism versus the pessimism index of a Chinese version of the Life Orientation Test

To examine the dimensionality of the Life Orientation Test (LOT) (a measure of optimism) in Hong Kong Chinese, a Chinese version of the LOT, a physical symptoms checklist, and the Chinese Affect Scale were administered to two separate samples of 230 undergraduates and 173 working adults. Exploratory factor analysis showed that the LOT was split between the optimism and the pessimism indices in both samples, but these two factors were not correlated differentially with either symptom reports or affective measures. On balance, the two indices dc differ in one important aspect. The predictive power of the complete LOT was conferred mainly by the optimism rather than the pessimism index. These findings indicate thai the two halves of the LOT measure the same construct of optimism, but the positive half or the optimism index does this more adequately. The two-factor solution was probably caused by difference in the direction of item wording rather than multidimensicnality. Therefore, the scale should be treated more appropriately as unidimensional for the reason of parsimony.