How do jurors three and ten allow their personal prejudices to blind them from seeing the truth?

3rd Juror is a small business owner. He proudly says that he started his business from scratch and now employs thirty-four workers. We learn early on that he has a bad relationship with his own son, with whom he is no longer speaking. We are led to believe that this is a contributing factor to his prejudice against the defendant, accused of stabbing his own father. 3rd Juror is the last to be convinced and only changes his mind once he realizes that he is only projecting his feelings about his own son onto the defendant.

3RD JUROR: Yeah, well I've got (a kid). He's twenty. We did everything for that boy, and what happened? When he was nine he ran away from a fight. I saw him. I was so ashamed I almost threw up. So I told him right out. "I'm gonna make a man outa your or I'm gonna bust you in half trying." Well, I made a man outa him all right. When he was sixteen we had a battle. He hit me in the face. He's big, y'know. I haven't seen him in two years. Rotten kid. You work your heart out...[He breaks off. He has said more than he intended. He is embarrassed.] All right. Let's get on with it. pg. 18

10th Juror is one of the most fervent attackers of the defendant. Tactless and fairly bigoted, he condemns the defendant as “one of them” right from the start.

What's goin' on here? I'm trying to tell ya... You're makin' a big mistake, you people! This kid is a liar! I know it, I know all about them! Listen to me... They're no good! There's not a one of 'em who is any good! I mean, what's happening in here? I'm speaking my piece, and you...

Listen to me. We're... This kid on trial here... his type, well, don't you know about them? There's a, there's a danger here. These people are dangerous. They're wild. Listen to me. Listen.