Examining the Measurement Invariance of the LOT-R Measure of Optimism in the United States and Japan

Western samples have demonstrated greater optimism than East Asian samples, however, the factor structure of the Life Orientation Test (LOT) is not always consistent. Measurement properties of scales may differ across cultures, potentially biasing estimation of group differences. This study examined the factor structure and measurement invariance of the LOT-Revised among Japanese and American adults. A representative sample of 1805 American and 1027 Japanese adults was utilized. CFA was used to compare 1-factor and 2-factor models of optimism within samples and examine the measurement invariance of the LOT-R across samples. The 2-factor model was superior and demonstrated partial weak invariance. Levels of optimism and pessimism were also compared across samples. Japanese adults demonstrated lower levels of optimism and greater levels of pessimism than American adults. Findings highlight the importance of assessing measurement invariance in cross-cultural research, suggest exercising caution when using the LOT-R, and provide evidence that optimism and pessimism function as separate constructs.