Objective: The present study aimed to investigate the relationship between Psychological Capital and Public-mindedness, and find the components of Psychological Capital that can predict Public-mindedness in the students of one secondary school.

Materials and Methods: The sample group consisted of 420 secondary school students. The data collection instrument was a questionnaire that contained the following three parts: a general Student questionnaire, the Thai Psychological Capital Inventory, and the Public-mindedness questionnaire. The following statistics were used to analyze the data: frequency, percentage, mean, standard deviation [SD], independent samples t-test, one-way analysis of variance [ANOVA], Pearson’s product-moment correlation coefficient and Stepwise multiple regression analysis.

Results: The level of Psychological Capital, Psychological Capital components (i.e., hope, self-efficacy, resilience, and optimism), and Public-mindedness in the sample group were moderately high. The comparison of Public-mindedness based on gender found that female students have a higher level of Public-mindedness than male students (p<0.01). The comparison of Public-mindedness based on class level found that students who studied at different class levels have different levels of Public-mindedness (p<0.001). Seventh grade students have a higher level of Public-mindedness than upper class level students (p<0.001). In addition, Psychological Capital and Psychological Capital components were positively correlated to Public-mindedness (p<0.001), and Psychological Capital components, such as self-efficacy, hope, and resilience can predict Public-mindedness in the sample group at 26.1%.

Conclusion: Psychological Capital was positively related to Public-mindedness, self-efficacy, hope and resilience are the components of Psychological Capital that could predict Public-mindedness in the sample group.

Keywords: Psychological Capital, Public-mindedness, Secondary school students