For emerging adults, the development of psychosocial intimacy may be a key developmental task shaped by past parenting. In this study, 232 emerging adult, college students completed a questionnaire about their intimacy development, identity development, self-efficacy in romantic relationships, parenting (i.e., attachment styles, parental caring and overprotection, and parental challenge), and well-being (i.e, depressive symptoms, loneliness, happiness, and self-esteem). Findings indicate that identity development, low attachment avoidance, and self-efficacy in romantic relationships predicted intimacy development. Furthermore, those individuals with high intimacy have less loneliness, greater self-esteem, and more happiness than those with low intimacy. Achieving psychosocial intimacy may have benefits for well-being.