Research has shown that parental relationships influence children's attachment styles. This study aims to extend this research by using extensive longitudinal data to understand how one’s attachment relationship with their parents in early adolescence may predict their attachment within romantic relationships in early adulthood. It was predicted that attachment style at 14 would be positively predictive of the same attachment style within teens’ later romantic relationships at age 24. The study further aimed to help explain such associations by examining whether or not specific attachment-related behaviors may help account for them. Finally, this study explored the potential role of gender identity for shaping one’s attachment style. It was hypothesized that male gender identity would predict more insecure attachment styles in adolescence and in later romantic relationships, and that female gender identity would predict more secure attachment styles in childhood and romantic relationships. Regression analyses were used to assess attachment at age 14 as a predictor of young adult romantic attachment quality at 24, and then attachment related behaviors at age 22 were examined as potential mediators. Analyses revealed a negative association between dismissive attachment quality to parents at age 14 and avoidant attachment to romantic partners at age 24. However, this association was mediated by dismissive romantic intimacy behaviors in adulthood. Furthermore, gender was identified as a predictor of attachment quality, as male gender identity predicted dismissive and deactivated attachment quality to parents at age 14 and avoidant attachment to romantic partners at age 24, while female gender identity predicted secure and preoccupied attachment quality to parents at age 14. Results show that gender does impact attachment quality in both adolescence and in romantic relationships, and that attachment quality to parents in adolescence is monumental to an individual’s quality of attachment in romantic relationships in emerging adulthood.