Objective: To investigate the relationship between psychological capital and social adaptability, and
to reveal the mediating role of achievement motivation, as well as the moderating role of only-child or not.
Methods: Totally 829 college students were surveyed with the Positive Psychological Capital Questionnaire,
Achievement Motivation Scale and Social Adaptability Diagnostic Scale. Results: (1) Psychological
capital positively predicted the social adaptability of college students, and achievement motivation
played a mediating role between psychological capital and social adaptability; (2) Only-child or not
moderated the second path of the indirect association. That was, only-child could adapt better under low
accommodation motivation than not only-child. Conclusion: Results reveal the relationship between
psychological capital and social adaptability and its mechanism, providing a new perspective for
improving individual adaptability.