How was Miss Emily in "A Rose for Emily" pyschologically affected by her father, and how did that bring about her murder of Homer?
Emily was isolated from society. Her father was strict, almost totalitarian. He mostly kept Emily at home and he definitely had a tight rein on what activities she was allowed to participate in. Emily's father was old society South, and he believed that his name and his family history placed him above his fellow townspeople. Therefore, Emily was not to associate with them.
By doing this, and by being physically and psychologically abused, Emily's father caused her to have a lonely life. It was rare for her to be friendly with anyone. Enter Homer. She becomes attached to him, and besides having a beau for the first time, she has a friend for the first time. Imagine the joy and the feeling of liberation.
But it was not to last. Homer was going to leave her. Emily had learned from her father to keep a tight hold on the things that she loved, and so the tightest hold she could get would be an eternity of togetherness. She killed him to prevent losing her only friend. Better to forever have his dead body than to have nothing at all.