When I consider Stevens' persona, a "chicken or egg" question comes to mind; is Stevens' lack of social ability due to his preoccupation with his job, or is he preoccupied with his job becuase he lacks social ability? (or perhaps he simply lacks the desire to interact socially?)
I think Stevens' extreme formality is best demonstrated in his recalled conversation with his father on pages 64-66. For example, Stevens adresses his father as "Father" rather than "you," even when speaking to him. Perhaps this is an attempt to impress his father, to whom he clearly aspires to be like; as Stevens stated earlier, his father did not speak eloquently or have a firm grasp of academic subjects.
Also, I agree with kevien that there are constant implications to Stevens' lack of willingness to move forward and accept change. Becuase of this, a particular statement he makes at the beginning of the novel-"there is no virtue at all in clinging as some due to tradition merely for its own sake" (7)-is becoming increasingly ironic.