Answer:
Harrison was rebellious, as well as tired of the handicaps. This can be shown in the scene where he publicly rips off his handicaps in front of national television. On the other hand, his father was so used to society being controlled by the Handicapper General that he did not care much about his handicaps. For example, although the father complains of the noise in his ears preventing him from thinking freely and being "above average," he does not do anything about it and rather just sits and complain.