Coming of Age, Satire
This story is most easily defined as an example of the coming of age genre; we see, sometimes literally, the shaping of a new, modern, popular Bernice from the somewhat dopy, old-fashioned, and unsuccessful original Bernice. Her transformation is at the core of the story, and, in the end, we get the feeling that the Bernice leaving this town is dramatically different from the one who showed up at the beginning of the summer, both inside and outside.
The story explores the idea of the modern woman's coming of age, as well – this isn't just a story about an unfortunate girl named Bernice, but can also be read as a commentary upon the birth of a new kind of American woman. This is where the satire kicks in. "Bernice Bobs Her Hair" pokes fun at the way in which this new modern woman defines herself – Marjorie's popularity boot camp mockingly shows us the rigorous routine the modern girl has to follow in order to keep up with the times. She must engage in the most ridiculous activities, such as inventing daring new stories to entertain men with, reading magazines to steal snippets of dialogue, and perpetually trying to pick up new admirers (dealing in quantity, not quality). This dizzying array of ludicrous pastimes makes us sympathize with Bernice, the old-fashioned girl, who simply never saw the point of some of this before. Fitzgerald slyly gets us to question the value of popularity and all its attendant hassles.