The possible negative impacts are numerous. Firstly, it can severely damage the self - confidence of the small boy in the story. He may feel that his own identity is not valid. Secondly, for the audience, especially young children, it can misguide them about the importance of respecting individual gender identity. It can also create a false perception that gender is something that can be changed against one's will, which is not only wrong but also harmful in a society that should be promoting acceptance and equality.
One negative impact is the confusion it can cause in a child's mind. A small boy might start to question his own identity in an inappropriate way. Also, it can give wrong ideas to other children who read or hear such stories.