These jurors want to end the trial fast and give the judge the most obvious verdict. Which is "Guilty." However, the #8 juror opposes to the so called obvious verdict, so the others get upset and angry. This also triggers their wanting to have a reasonable answer to their discomfort. They continously show disrespect to the #8 juror redirecting the attention to some jokes and games showing their disatisfaction till the first big point is made. And it goes on shifting one by one to the otherside. However, the #8 juror started it because he only wanted to hear more about the boy's life and his circumstances. But as the conversation went on the small points made by others helped him think of ways to prove the kid "not guilty." Thats what I think.