This dude is the only foreigner in the group of jurors, which might be the reason why he seems to appreciate their democratic rights and freedoms more than anyone else. For example, when some of the jurors want to know who changed their original vote from Guilty to Not Guilty, Juror #11 steps in to say, "Excuse me. This was a secret ballot. We agreed on this point, no? If the gentleman wants it to remain secret—" You might also notice here that the guy is very polite compared to his American-born fellow jurors.
As the movie unfolds, Juror #11 seems to take more opportunities to remind the other jurors about how important it is for them to reach a verdict that is fair and moral. As he tells the entire group, "We have a responsibility. This is a remarkable thing about democracy. That we are … what is the word? … Ah, notified! That we are notified by mail to come down to this place and decide on the guilt or innocence of a man we have not known before. We have nothing to gain or lose by our verdict. This is one of the reasons why we are strong. We should not make it a personal thing."
In some ways, Juror #11 could be giving us the thesis statement of the entire movie here. Like the movie, he is optimistic about how great it is that he and his fellow men have the opportunity to act as jurors and to make the best possible decision through democratic voting.
Despite all his happy talk about democracy, Juror #11 shows his mean streak when he realizes that Juror #7 has just been voting for whatever verdict will help him make the opening pitch for a baseball game. He shows his disgust by saying, "What kind of a man are you? You have sat here and voted guilty with everyone else because there are some baseball tickets burning a hole in your pocket."
Juror #11 is especially angry that someone like Juror #7 takes all of his freedoms and responsibilities for granted, while an immigrant like #11 probably knows what it's like to live without these things. His anger makes a lot of sense, and it goes to remind us that democratic processes, like sitting on a jury, are actually a pretty serious deal.