In "The Scarlet Ibis," the plot, first-person point-of-view narration, and dialogue are all used to convey the cruelty and malice of the brother. The first-person narration is told by the point of view of the brother. As such, the reader is able to gain direct insight into the thoughts, feelings, and motivations of the brother in relation to Doodle and his desire to help Doodle purely because he is ashamed of his disability/illness.
The plot is centered around the brother relentlessly pushing and bullying Doodle into exerting himself, until Doodle dies as a result of the brother's cruel, selfish insistence on making Doodle resemble a healthy, "normal" sibling.
Through the dialogue between the brothers, the reader is able to see how Doodle repeatedly seeks kindness and empathy from the brother, and how the brother often responds with pushiness and an insistence that Doodle needs to be "normal." As Doodle heart-wrenchingly calls out for his brother at the end of the story, the brother's refusal to respond potently illustrates Doodle's isolation and the brother's malice and cruelty towards him.
In "The Use of Force," the cruelty and malice of the doctor is mainly conveyed through the first-person point of view and plot. The doctor's first-person narration allows the readers to gain insight of his thoughts, which convey the disgust the doctor feels for the parents and the rage and lack of compassion he feels for the sick child. The readers learn as the doctor shares his thoughts that he sees the child as a "savage brat" who he has become so furious with that he enjoys causing her pain and fear.
The plot also conveys the cruelty of the doctor as the entirety of the story is centered around his increasingly harsh use of force against the little girl to obtain the throat sample.