There might not be one right answer to this question, but in my opinion, the major theme of this story is the subjugation, imprisonment, and disrepect of the female in marriage. Throughout the entire story, the wife's expressions of her feelings and needs are completely disregarded. Who is the woman in the wallpaper who is trying to escape? She stands for the female protagonist, but also for all women who are trapped in marriage. If you look up the date of publication for this story, you will find that it was written long ago, and was quite ahead of its time in discussing this theme. Is this an important theme in today's world? What evidence is there to show that married women's lives have or have not improved?
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The prevalent theme in Charlotte Perkins Gilman's short story "The Yelllow Wallpaper" is the supression of the female role and expression. The way that this prevalent theme is treated is through the use of a situation that is unique to women- pregnancy and motherhood- and by making this situation turn into a problem for the main character. All this, simply because society is too ignorant to concede women like the narrator with the tools and resources that they need in order to fulfill the social expectations of nurturers and protectors that are bestowed upon them.
The unnamed narrator is going through what she describes as "nervous prostration"; the equivalent of what modern medicine would call "post-partum depression". Set in a historical time when medicine nor psychology were dedicated to the study of women, the woman's condition is treated in a near-barbaric way by isolating her, by depriving her of any mental stimulation, and by forcing her to submit to these rules "for her own sake".
As a result, the woman's sense of normalcy begins to dwindle between boredom, the recovery from pregnancy, hormones, and the lack of support that she is getting, overall. In the end, she starts "seeing things"; namely, the shape of a woman forming in the yellow wallpaper that begs to be liberated from her confined existence on the wall. This is an allegory to the narrator, herself.
I kept on creeping just the same, but I looked at him over my shoulder.
"I've got out at last," said I, "in spite of you and Jane. And I've pulled off most of the paper, so you can't put me back! "
"The Yellow Wallpaper" is a good study not only in human psychology, but also in women's history. The story is not set during ancient times, but during a time where a lot of scientific discoveries and new paradigms were beginning to surface. Unfortunately, women continued to be left behind during the late 19th century and it has taken a lot to get to the point where society is now in terms of scientific and psychological understanding. This is what makes the story worthy of further analysis and study.