First off, lets go over each character in the jury and how each of them contribute to the dynamics of the group as a whole. Every juror in this movie plays a part in the decision making processes of this movie. In a way you could say that Henry Fonda was the star and the 11 other jurors all played co-stars within the movie.
Thefirst juror, Juror number1, unfortunately was appointed the task of being the foreman of the jury. He in my opinion didn't initially conform to the social pressure that members of juries tend to do. I think he had the basic thought that the kid was guilty before the jurors even convened in the room. Later on, when he does decide to change his mind to not guilty, I also believe that he didn't conform to social pressure, but simply reviewed the facts and decided there was a "reasonable doubt" that the kid could be innocent.
The next juror, Juror number 2, is a very shy and timid man. At the beginning of the movie, it's really hard to tell whether the man's decision of being guilty is influenced by the group or whether he formed his opinion strictly from the court case. The reason I think this is because he really doesn't do much talking in the beginning, but eventually comes into his own later on and actually voices his opinion.
Juror number 3, and probably the most controversial