How does the climax of the story reflect the narrator’s psyche?
The revelation of the secrets he has literally and figuratively imprisoned behind the wall and the divulging of the true depths of his menacing and reprehensible nature are simply the culmination of the dark desires that have existed within the narrator. When the dead body of his wife is exposed for all the world to see, it is also representative of his psyche being laid bare to the world.
What is ultimately exposed as the real “spirit of PERVERSENESS" that the narrator tries to explain away as a “primitive impulse of the human heart,” and how does it contrast with the narrator's lackluster explanation?
The narrator tries to explain his horrific cruelty to the cat or cats as one's primitive impulse to do something vile simply as a reaction to knowing that one should not do that thing. This is a facile explanation and only a hint of the real show of perverseness that is to come. By the end of the story, it has become clear that the real spirit of perverseness that grips the narrator (and by extension that part of the human race given to such demonstrations of primitive behavior) is the base unwillingness to show remorse or take responsibility for one’s actions that can be explained away by those who desire to shift responsibility away from themselves and place it onto a universal drive. The only perverseness manifested in the story is located within the individual: the unnamed narrator that cannot accept that he is beyond the primitive and living closer to the realm of the insane.
Why does the narrator hate his wife and end up killing her?
First, it is important to note that the text ultimately leaves this ambiguous: there is no clear answer as to why the narrator feels and acts this way, but this is one of the reasons why the story is so compelling. The narrator may simply be insane—he has lost touch with reality and cannot distinguish right from wrong anymore, so since it feels good to let his id take over and be violent towards creatures in his way, his wife bears the brunt of it. He may also see his wife as a problem—perhaps she is a rival for the first cat's affections, or perhaps she is a silent witness to the depraved acts the narrator commits and he must get rid of her. He may also be out of his mind with alcohol and not able to judge what he does or what the effects might be. The second black cat may be a phantasm urging him to commit evil, or it may be his guilty conscience becoming so oppressive that he cannot think clearly. All of these are possibilities, though it is up to the reader to decide which is/are the most persuasive.