Western theories suggest that self-concept consistency is important for well-being, but cultural psychologists have proposed that this relationship may be weaker in collectivistic or dialectical cultures. Hypotheses regarding the ability of self-concept (cross-role) consistency and short-term stability to predict hedonic and eudaimonic well-being across cultures were tested. College students in the United States, Australia, Mexico, Venezuela, Philippines, Malaysia, China, and Japan rated their traits in various roles at test and retest and completed measures of hedonic and eudaimonic well-being. In all cultures, cross-role consistency and short-term stability were inversely associated with negative affect, an aspect of hedonic well-being, and positively associated with Big Five Emotional Stability. In contrast, cross-role consistency and short-term stability were related to eudaimonic well-being more reliably in individualistic cultures than in collectivistic cultures, although the results in China only partially conformed to this pattern. We concluded that cross-role variability and short-term instability of self-concepts have a significant temperamental or affective basis and this temperamental basis is a cultural universal. In addition, cultural psychology predictions of a weaker relationship between self-concept consistency and well-being in collectivistic cultures, as compared to individualistic cultures, was largely supported for eudaimonic well-being.Keywords: culture, cross-role consistency, short-term stability, hedonic and eudaimonic wellbeing, individualism-collectivism, dialecticism SELF-CONCEPT CONSISTENCY AND WELL-BEING 3 Self-concept consistency has been defined in a variety of ways and different consistency constructs may relate differently to well-being (Campbell, Assanand, & Di Paula, 2003). In the present study, we define self-concept consistency as the consistency of individuals' trait ratings across different roles, and refer to this construct as cross-role consistency (see also Boucher, 2011;Church, Anderson-Harumi et al., 2008) According to theory (e.g., Jahoda, 1958;Jourard, 1965) and empirical findings (Campbell et al., 2003;Church, Anderson-Harumi et al., 2008;Donahue, Robins, Roberts, & John, 1993; Sheldon et al., 1997), a consistent and stable self-concept is important for adjustment or wellbeing, at least in Western or individualistic cultures. However, cultural psychologists have hypothesized that the relationship between consistency and well-being may be weaker or nonexistent in collectivistic cultures, where self-concept flexibility and adaptability to situational contexts are valued (Markus & Kitayama, 1998;Suh, 2002). Indeed, Suh (2002), in a comparison of cross-role consistency in Americans and Koreans, found support for this hypothesis, and attributed the cultural differences to differences in self-construals.Alternatively, English and Chen (2007) and Boucher (2011) attributed the hypothesized weaker relationship between cross-role consistency and well-being in East...