* Juror 8's persistence: Juror 3 is deeply convinced of the boy's guilt. He sees the evidence as clear-cut, and Juror 8's insistence on scrutinizing it and raising doubts infuriates him. He feels Juror 8 is wasting time and holding up the process.
* Juror 8's perceived disrespect: Juror 3 interprets Juror 8's willingness to challenge the consensus as a personal attack. He feels disrespected, as though Juror 8 is questioning his intelligence and judgment. This is further fueled by Juror 8's calm demeanor, which Juror 3 perceives as arrogance.
* Personal connection: Juror 3's own experiences as a father and his anger towards his son are projected onto the case. The boy's disrespect and rebellion remind him of his own son, and he feels a need to punish this "disrespectful" behavior, even if it means convicting an innocent boy.
* Fear of change: The play explores themes of prejudice and societal pressures. Juror 3 is resistant to change and the discomfort of challenging his long-held beliefs. Juror 8's questioning makes him confront his own biases and insecurities, which he reacts to with anger.
It's important to note that Juror 3's anger isn't solely directed at Juror 8. It is a complex mix of his own personal struggles, his deeply ingrained beliefs, and his unwillingness to consider alternative perspectives.