This study examined differences of irrational beliefs and mental health in undergraduates ( N =151) categorized into four groups based on prosocial behavior and overadaptation, respectively: High–High, High–Low, Low–High, Low–Low. The results showed that the scores for both irrational beliefs and mental health for the High-High group were higher than for the other three groups. The importance of treating oneself with kindness while helping others was discussed.