Subjective well-being (SWB), people's emotional and cognitive evaluations of their lives, includes what lay people call happiness, peace, fulfillment, and life satisfaction. Personality dispositions such as extraversion, neuroticism, and self-esteem can markedly influence levels of SWB. Although personality can explain a significant amount of the variability in SWB, life circumstances also influence long-term levels. Cultural variables explain differences in mean levels of SWB and appear to be due to objective factors such as wealth, to norms dictating appropriate feelings and how important SWB is considered to be, and to the relative approach versus avoidance tendencies of societies. Culture can also moderate which variables most influence SWB. Although it is challenging to assess SWB across societies, the measures have some degree of cross-cultural validity. Although nations can be evaluated by their levels of SWB, there are still many open questions in this area.