When Jo calls Richard “crazy” and “boy,” it shows her inability to understand his legitimate grievances about the way she and Lyle have treated him. Rather than understanding that he’s been insulted for his race, she typecasts him as “crazy” and once again calls him “boy,” an insulting way to refer to an adult Black man. Her pleading with Lorenzo, on the other hand, hints that she’s not actually afraid of Richard: she’s afraid of
Lyle and what Lyle might do to Richard. Meanwhile, when Richard insults Lyle as “ball-less” and knocks Lyle down, it shows Richard asserting his masculinity in the face of racist emasculation through name-calling and violence, which may ultimately not help Richard achieve the self-respect he is seeking.