How is pride featured in "The Scarlet Ibis"?

The brother's pride is the driving force for what occurs in the narrative of James Hurst's "The Scarlet Ibis."
The narrator/ brother initially describes his little brother, to whom he gives the nickname Doodle, as a "disappointment" and "a burden." Clearly, the little brother is an affront to the narrator's pride. At first, Doodle just lies on a rubber sheet and does not seem to be "all there." Later, he does develop some, but he still cannot walk. As a result, the proud brother, who is embarrassed to do so, must pull Doodle in a go-cart his father made for him. Because of this perceived affront to his pride, the brother insists Doodle learn to walk. They practice secretly because the brother knows he should not strain Doodle, whose heart is weak. Nevertheless, he pressures Doodle to practice for weeks until he can finally walk. The boys decide not to reveal this learned skill until a special occasion occurs; they choose Doodle's sixth birthday. After bringing Doodle to the doorway of the dining room in the cart, the brother tells all the other family members to turn their backs and not to peek around. He helps his brother up. While Doodle stands, his brother tells the family they can now look.

There wasn't a sound as Doodle walked slowly across that room and sat down at his place at the table.

When the adults see Doodle walk slowly across the room and sit down at the table, they are overjoyed. When they congratulate the brother, who Doodle credits with his accomplishment, the brother suddenly begins to cry in shame. 

They did not know that I did it for myself; that pride, whose slave I was, spoke to me louder than all their voices; and that Doodle walked only because I was ashamed of having a crippled brother.

Later on, in the summer, the brother gives Doodle swimming lessons and tries to teach his brother to row a boat because he does not want to be embarrassed by Doodle before school begins. The stress upon Doodle is apparent, as he looks feverish and does not sleep well. Nevertheless, in his blind pride, the brother pushes Doodle to keep working.

I should have already admitted defeat, but my pride would not let me. . . It was too late to turn back, for we had wandered too far into a net of expectations and had left no crumbs behind.

Even the appearance of the omen of the scarlet ibis, a delicate and beautiful bird who wanders too far out of its element and dies, does not arrest the brother in his selfish drive to make Doodle normal. Shortly before school begins, the brother takes Doodle out on the water and makes him row back against the tide and the approach of a storm. When they finally reach shore, Doodle is exhausted, and as the rain begins to pelt them, Doodle falls behind his brother in their rush to get home. "Brother, Brother, don't leave me! Don't leave me!" he cries, but the pride and the "streak of cruelty" in the brother emerges as he is its "slave," and he runs as fast as he can. When he finally turns back for Doodle, the narrator finds his piteous brother limply seated with his face buried in his arms. When his brother moves Doodle, he falls backward onto the earth, dead. Just as the beautiful and fragile scarlet ibis has died, both the ibis and Doodle are victims of a certain pride that has pushed too far.