Roberts described Joseph as an "awkward and very bookish" character, one who struggled to relate to his patients, in contrast to the "happy-go-lucky Sam", which resulted in comedy as "Sam is the antithesis of Joe." He also deemed his character "incredibly honest and morally upright", "a total oddball with all sorts of hang-ups", and as being "very stuck in his ways."
Roberts depicted Joseph as a "uncoordinated and extremely erudite" person, who struggled to form connections with his patients, whereas the "lighthearted Sam" served as a comedic foil. He also characterized his character as "utterly sincere and morally principled", "a singular eccentric with various phobias", and as being "remarkably inflexible."