Environmental reward (ER) is an established mechanism contributing to depression. Given the high prevalence of depression in China and Taiwan, it is important to develop measures that facilitate the examination of cultural similarities and differences in ER. The reward probability index (RPI) assesses ER through items measuring individual access to rewarding (Reward Probability) and aversive (Environmental Suppressor) events. The purpose of the current study is to translate the RPI into Chinese (C-RPI) and to study cultural difference in ER by examining structural- and item-level differences in RPI functioning. A total of 930 college students were recruited from China (n = 300), Taiwan (n = 300), and the United States (n = 330). Confirmatory factor analysis was used to study the configural invariance of the RPI and C-RPI. Item response theory-based differential item functioning (DIF) testing was used to study item level differences in functioning between the RPI and C-RPI. Results overall support the established RPI structure in all three regions. Most Reward Probability items exhibit no DIF across cultures, while most Environmental Suppressor items exhibit DIF across cultures. Findings highlight cultural difference in ER constructs and cultural factors contributing to the observed DIF. The assessment and clinical implications of the findings are also discussed.
