The adaptation account suggests that the persistence of some traditional values in modern society is due to their enduring adaptive utility. We tested this hypothesis by examining the change of filial piety in two Confucian societies, China and Japan. By analyzing natural language data, Study 1 found that Chinese people’s concern about and liking for filial piety have increased since 1979, with falling birth rate and rising elderly population as the Granger causes. By analyzing survey data from 2006 to 2017 ( N = 7,283) in China, Study 2 found that reciprocal filial piety was adaptive (i.e., conducive to well-being) and increasing, whereas authoritarian filial piety was maladaptive (i.e., detrimental to well-being) and decreasing. By analyzing both Japanese language data from 1989 to 2023 (Study 3a) and survey data from 2006 to 2018 (Study 3b: N = 4,763), Study 3 replicated the main findings from China. These findings support the adaptation account of cultural persistence.