The short story "Charles", by Shirley Jackson, has two prevalent themes: identity and gender.
The theme of identity is identified by the fact that Laurie's mother has no clue that the child, Charles, her son is talking about is, in fact, her own son. The theme is compounded by the way that Laurie's parents fail to see his behavior as inappropriate, but they both see the problems with the behaviors of Charles. The parents cannot identify the behaviors of Charles with those of their own son. Therefore, the parents have no clue who their child really is.
Another way to examine this theme is through examining Laurie. He does not seem to have a full grasp on his own identity (not surprising given he is only in Kindergarten).
The second theme defined in the story is one of gender. Many people would align the name of Laurie with a girl. The name Laurie is not typically associated with that of a boy. The name which Laurie uses as his alternate ego is, by far, much more masculine. Therefore, one could justify that Laurie has issues with his own assumed feminine identity and needs to create a more masculine one. He does this by creating Charles, a boy who speaks inappropriately and behaves like the "typical boy."
One theme of "Charles" is that of parental myopia. Throughout the story, the mother, who acts as narrator, is prevented by her leniency and indulgence from perceiving that it is her own son who commits the acts attributed by him to a boy named Charles.
From the beginning the mother vacuously describes her son's change on his first day of school by narrating that Laurie transforms from a "sweet-voiced, nursery-school tot" to "...a swaggering character" who does not bother to say good-bye to her. Later, at lunch he is "insolent" in his tone when speaking to his father, then he remarks that his teacher has told him that they, his parents, are not to take the name of the Lord in vain. Yet neither parent questions him on how the teacher knows that they use the Lord's name, nor corrects him about his disrespectful tone.
Oblivious to the misbehavior of their son, the parents of Laurie listen eagerly to what Charles has done each day with no deduction that Laurie attributes his bad behavior to a fictional boy. Foolishly, the mother finally attends a P.T.A. meeting and asks the teacher about Charles only to be told "We don't have a Charles in kindergarten." It is only then that the parent discovers the true personality of her child.