Bateman murders several people throughout the course of the film. Killing is a bad habit that he seems to have ironically picked up to keep from going insane from being so alone in his life. This lonelyness is the second critique of the nation's elite: They don't listen to others and only care about themselves. The audience learns this after Bateman exploits this fact in most of his conversations. He often interjects with comments on how he can't stop killing people or how he doesn't care about whatever his co-workers or spouse are thinking or talking about but the person on the other end of the conversation never notices; They are completely self-obsessed to the point where they only hear what they want to hear.
American Psycho is a great movie to watch with friends for laughs and scares but, when looked at more closely, is really a message about the sad, corrupt lives being led by Wall Street professionals.
American Psycho (Business Card Scene)