My thesis tries to explain the function of bullying as a pro-group behavior in the light of evolutionary psychology, while considering its contribution to the whole group. Nonetheless, with the understanding of groups' benefits from bullying, we do not disregard its negative consequences for individuals. We believe that having a better understanding of bullying behavior will help us to intervene as educators in the future and prevent negative consequences. In addition, I work with Prof. Gumpel and his associates, Prof. Yifat Kulikant-Ben David, Mor Nachum, and Judah Koller, on the BLINK project (Behavioral Intervention in Kindergarten).