Doctor Nemur is the psychologist who developed the theories behind the experiment used on Charlie.  He is ambitious and anxious to reap the glory of being able to raise Charlie's intelligence; he cares little about Charlie as a person.  Initially against using Charlie as his subject, he later feels threatened when Charlie's intelligence grows to surpass his own.

Doctor Strauss is Nemur's partner, a neurosurgeon who performs the operation on Charlie.  In contrast to his academic counterpart, Strauss is much more humane.  Skilled in the scientific aspects of the experiment, Strauss also is concerned with the effects his intervention has on Charlie as a person.  He helps Charlie adjust as his intelligence develops, and continues to try to support him when the effects of the experiment wear off.

In his natural state, Charlie thinks Joe Carp and Frank Reilly are his friends, even though they constantly make fun of him and make him the object of practical jokes.  When Charlie's mental capacity is at its height, he understands that, for people like Joe and Frank, "it had been all right as long as they could laugh at (him) and appear clever at (his) expense, but...(his) astonishing growth...made them shrink and emphasized their inadequacies" (May 20).  Charlie is able to perceive that Joe and Frank tormented him to make themselves feel important, and when they can't do that anymore, they react with anger.