A well-documented finding in the literature is that members of many East Asian cultures report lower self-esteem and psychological well-being than do members of Western cultures. The authors present the results of four studies that examined cultural differences in reasoning about psychological contradiction and the effects of naive dialecticism on self-evaluations and psychological adjustment. Mainland Chinese and Asian Americans exhibited greater "ambivalence" or evaluative contradiction in their self-attitudes than did Western synthesis-oriented cultures on a traditional self-report measure of self-esteem (Study 1) and in their spontaneous self-descriptions (Study 2). Naive dialecticism, as assessed with the Dialectical Self Scale, mediated the observed cultural differences in self-esteem and well-being (Study 3). In Study 4, the authors primed naive dialecticism and found that increased dialecticism was related to decreased psychological adjustment. Implications for the conceptualization and measurement of self-esteem and psychological well-being across cultures are discussed.