Despite high profile examples that are highlighted in the popular media, we know little about high-cost prosocial behaviors such as defending and including, and how these behaviors might change over time and vary by individual. Thus, this study explored defending and including behaviors across the transition to adulthood by assessing growth and profiles of these high-cost prosocial behaviors over a four-year time span. In addition the study explored gender, emotional (sympathy), cognitive (personal values), individual (self-esteem), and relational (maternal warmth) factors during adolescence that predicted profiles of defending and including during the transition to adulthood. Participants were 469 individuals (52% female, 70% European American) who participated at four time points (ages 18–21). Growth curve analyses showed that defending and including behaviors decreased slightly across the transition to adulthood and these behaviors tended to vary as a function of the target of the behavior. Latent profile analyses revealed three groups at each age, one with low, one with medium, and one with high levels of defending and including. The discussion focused on the prevalence and change in defending and including behaviors during the transition to adulthood, as well as the variability that exists in high-cost behavioral profiles.