In 1952, an article was published in the Journal of Psychology that sought to unearth the causes of anti-Semitism (Morse & Allport, 1952). What the authors found was that the variables related to anti-Semitism included physical behaviors (i.e., discriminatory actions), verbal behavior (i.e., derogatory comments), and aff ective states (i.e., feelings of aversion). Th e authors also concluded that no one factor could be delineated as the only cause of anti-Semitism. Th e complexities of behaviors that comprise discrimination have been studied for over 60 years. When the fi rst edition of this book was published in 2004, we argued that bullying had to be studied across individual, peer, family, school, community, and cultural contexts (see Figure 1.1). Like discrimination, bullying is a complex phenomenon, with multiple causal factors and multiple outcomes.