Both of the main characters in “The Yellow Wallpaper” suffer from their inability to differentiate between outward appearances and internal realities. In fact, the story’s conflict can be traced to this flaw in their perceptions: the narrator’s husband is unwilling to believe in an illness without physical symptoms, and the narrator believes that the complex images in the wallpaper’s pattern demand investigation. 

John’s manifestation of this theme is apparent in the way he treats the narrator throughout her recovery. One of the earliest statements the narrator makes about her condition is that her husband “does not believe [she is] sick.” He is invested in her recovery from her “temporary nervous depression,” but all of his prescriptions involve her physical health rather than her mental health. John pushes the narrator to rest, eat iron-rich foods, take supplements, and exercise on a set schedule. Her observed physical condition indicates to him that she is recovering as hoped, and he disregards the narrator’s statement that she doesn’t feel any better in her mind. To John, the narrator must use her “will and self-control” to master her condition, and not “let any silly fancies run away” with her. His attitude is in keeping with general beliefs in the field of psychiatry at the time Gilman was writing, which did not clearly differentiate between mental and physical health. John’s—and by extension, medicine’s—inability to see that the mind could have an illness independent of the body prevents the narrator from receiving the type of help she needs before her condition has become unmanageable.

The narrator herself also misreads an appearance: that of the yellow wallpaper itself. While at first she is struck only by the ugliness of the pattern, over time its visual complexity draws her into spending more and more time contemplating it. Eventually, it becomes the center of her emotional world and the focus of her delusions. A careful reader, however, should note that the narrator’s vision of the wallpaper is the result of the pathetic fallacy. The fantastical, shifting images within the wallpaper are a projection of the narrator’s imagination, not an accurate account of the wallpaper. Thus, where the narrator believes she is seeing external reality, she is actually seeing a manifestation of her internal reality.

Both of the main characters in the short story are predominately preoccupied with outward appearances. John focuses on his wife’s physical improvement instead of her mental state, while the narrator trains her attention on what seems to be the physical appearance of the wallpaper, which only worsens her mental agony. Through “The Yellow Wallpaper,” Gilman asserts the importance of looking inward by illustrating the perils of solely focusing on outward appearances and demonstrating the dichotomy between inner and outer worlds.