Life experiences for corresponding age cohorts in the United States (US) and the People's Republic of China (PRC) have been dramatically different. If cohort effects account for cross-sectional age differences in mean levels of personality traits, different patterns of age differences should be seen in samples from the US and the PRC. The present study examined scores on scales from the California Psychological Inventory (CPI; Gough, 1987) in US (N = 348, age = 19-92 years) and PRC (N = 2,093, age = 18-67 years) samples. Very similar patterns of age correlations were seen. To compare results to other cross-cultural studies, CPI scales were interpreted in terms of the Five-Factor Model (FFM) of personality; an FFM Age-Relatedness Index based on American data accurately predicted CPI age correlations not only in the US but also in the PRC sample. Results are consistent with the hypothesis that there are universal intrinsic maturational changes in personality.