Sonny "makes his bones" at the age of 19. By his mid-20s, he is promoted to a "caporegime" in the Corleone family. By the end of World War II, he is his father's underboss and heir apparent, popular and feared as a merciless killer with a short-temper. Sonny is not without a sensitive side, however; at age 11, he brings home a homeless boy, Tom Hagen, demanding he be allowed to live with the family. Vito informally adopts Hagen, who eventually rises through the ranks to become Vito's "consigliere". As the eldest child, Sonny acts as protector to his younger siblings and has a soft-spot for his youngest brother, Michael. While he can beat up and kill other men without hesitation, he cannot bring himself to harm women, children, or anyone unable to defend themselves.