I do believe Parris changes by Act IV. I know he is humbled by the fact that his niece Abigail has run off with all his money. He is left with nothing and this causes him humiliation. However, I believe that Parris is still worried about himself. He is worried about the physical threats on his life. He is afraid that he will be harmed. Overall, I believe that he has changed because he is not as worried about his reputation. Now, he has something more than his reputation to worry about. He has to worry about his life. No doubt, this will change a man. Nonetheless, Parris is still obnoxious in that he only cares about himself. He is not a true servant to the people.
Parris can be described as a flat character. He does not undergo any significant change in his character and the qualities he presents. For Parris, the truth of the accusations of witchcraft in Salem is not an issue. Unlike Hale, Parris never doubts the virtue of his actions. He only begins to doubt the effects of his actions and to wonder about the consequences of his role in the trials as they might impact his personal safety and position.
The changes for Parris consist largely in his sense of security.
As challenges to the validity (both moral and legal) are brought against witch trials in communities surrounding Salem, Parris worries that the court in Salem may be subject to the same challenges.
Parris fears that the hanging of two such upstanding citizens as Rebecca Nurse and John Proctor the next morning will incite a rebellion in Salem similar to the one in Andover
He also worries about physical harm being done to him as a result of his role in the trials.
Parris was once a bully in the pulpit, demanding more respect and more pay from the members of the church. When we reach the end of the play, Parris is afraid for his life and casting about for a way to redeem the court proceedings.
Although his circumstances change, I would argue that Parris does not change much throughout the play. By the end of Act 4, he has not learned much.
Although Parris is concerned about his daughter, he seems more concerned about what others think about him. When unnatural causes for his daughter’s condition are considered, he panics.
No - no. There be no unnatural cause here. …Let him look to medicine and put out all thought of unnatural causes here. There be none. (act 1)
Parris gets behind the witch trials because they reinforce his importance in the community. He does not seem to care that innocent people are being hurt. He hangs on to the trial even when he is being unreasonable.
Parris: Why could there not have been poppets hid where no one ever saw them?
Proctor, furious: There might also be a dragon with five legs in my house, but no one has ever seen it. (act 3)
In the end, Parris does not relent. He continues to insist that Proctor confess. When he is robbed by Abigail, Dainforth says he is a “brainless man” (act 4). He may be broke, but he is as intractable as ever.