Many critics of the Metamorphosis have argued that Gregor's turning into a giant insect is but one of several examples of a character "morphing" in some way from one state to another. An example of this would be Gregor's morphing, compared to his sister Grete; Gregor morphed physically, while Grete morphed mentally and emotinally. Franz Kafka appeared to have used these metamorphosis to show how the characters viewed themselves, others, and the world in general.
In the Metamorphosis, Gregor Samsa morphed into a cockroach/beetle type insect overnight; before his change, his family was dependent of him because Gregor was the source of money and their way of paying all of his father's debt off. Though when Gregor morphed, all of this completely changed; Gregor's metamorphosis caused him to now be the dependent of his family. Gregor needed their help and care, in order to survive. It appears to most readers that Gregor could now "step outside the box", and see what it was like to be the one recieving the help instead of giving the help. Before this, Gregor really didn't focus on much of anything, besides working. Back then he saw himself as a useful source to his parents. But when he morphed into the insect he saw himself as a burden to his family; someone(thing) that was just in their way and causing them unnecessary pain. Because of all of the time spent in his room, Gregor now had the opportunity to actually look outside of his window and view the world (even though his vision was becoming blurry and colorless). Gregor continued putting his family's feelings before his own, as he had been doing, and decided the only way to give them their peace and happiness back, was to leave them in some way.
Though, while Gregor was morphing physically his sister was also morphing; Grete Samsa had started out in the beginning of the Metamorphosis as a young teenage girl, whose parents had viewed as a child and a useless person. Grete felt that she was not useless, but needed a way to prove that to her parents. And when Gregor first morphed, she appeared to have sorrow and sympathy for him, but also used his change, as an opportunity to prove to her parents that she was not the useless child they thought her to be.
Grete, in the beginning, was the only one who was providing care for Gregor and trying to help him adapt to this change (bringing him food, cleaning his room, etc.). And after the Samsa's maid left, Grete even began doing household chores such as cooking and cleaning, and also working, while still providing care for Gregor. Eventually, her mother and father had changed their opinions about her. Yet, it appears that not long after her parents began to view her positively, her care for Gregor began to diminish; she had accomplished what she wanted (her parents appreciation), and because of that, she had changed into a beautiful young woman.
Franz Kafka used their changes in the novel, to show how people's attitude towards certain things can change completetly, once they are presented a different situation to be in, and have to step into someone else's shoes; Gregor went from a workoholic to someone who now depended on his parents and sister for his everyday survival; while Grete went from a quiet young girl, to a confident young woman. Gregor and Grete's changes throughtout the Metamorphosis differed in several ways, but both of their changes had an effect on how they viewed themselves, others, and the world.