Shame makes narrator kill brother, Doodle - better off without brother OR emotion that narrator feels when Doodle dies = fear?
While Doodle’s brother was motivated by pride, we cannot deny that they did enjoy spending time together. In fact, if you take away Doodle’s disability, there relationship was a pretty typical brother relationship. Doodle’s death was not out of fear. Like the scarlet ibis blown off course by the storm, Doodle just gave out trying to out run the storm.
Another force motivates Doodle's brother, also, and that is pride. He takes pride in himself for bringing Doodle along physically. The brother sees Doodle's successes not in terms of the little boy's courage and determination, but as proof that he himself has accomplished a great deal as Doodle's teacher. The brother's pride is selfish and destructive. At the end of the story when Doodle fails, the narrator reacts in a burst of anger, cruelty, and frustration because Doodle's failure is also the brother's failure. He remembers, "The knowledge that Doodle's and my plans had come to naught was bitter, and that streak of cruelty within me awakened." He also speaks of "the flood of childish spite" that had overwhelmed him. When he runs away from Doodle in the storm, it never occurs to him that his little brother will die. Brother had never considered just how far and how hard he had pushed Doodle out of his own childish and selfish need.
I'm not sure that any of your statements are entirely accurate. The first statement is probably nearest to the truth but it implies that Doodle's brother kills him as an act of will. As the narrator of the story, Doodle's brother tells his tale from the perspective of an adult looking back with the wisdom gained by adulthood. He now realizes that he was ashamed of his brother and pushed Doodles so hard so Doodle would be perceived as "normal". However, Doodle's brother really did not expect his brother to die. With hindsight, he now realizes he pushed his brother to the limit and simply was too young himself to fully understand that by leaving Doodle and forcing him to try to catch up, Doodle's heart could not keep up. As an adult looking back, Brother is now ashamed of his actions but as a child he was embarrassed by Doodle, especially the notion that Doodle would soon go to school and all his friends would see him. his impatient actions, especially the act of leaving Doodle alone, caused Doodle's death but Brother did not plan the death.