In the novel To Kill A Mockingbird by Harper Lee, Atticus’s closing argument was unsuccessful. In Atticus’s closing argument, he makes it so the jury will assuredly understand. The Jurors are all white and from out of town so they are biased and don’t know the townspeople and how they behave. Atticus tries to connect with the Jury but he was ineffectual. Atticus’s closing argument was not effective because of cognitive bias and he couldn’t persuade his audience. Cognitive bias is shown in the closing argument. In the closing argument, he states “This case is as simple as black and white.” All of the evidence was there but they were so biased that they wouldn’t listen. Atticus found all of the facts and laid it out in front of them