I'm not sure if it's necessary to seem dull...

At least for the case I was sworn on*, both prosecutor and public defender seemed to just want alert, impartial jurors who wanted to be there and weren't stressed from loss of wages (juror stipend is a joke) or unhealthy.

I was ~19 but had graduated from high school at 16, been a intern journalist and copy editor for the local paper, and adults told me I seemed like an old man since I was ~10. I took more notes during the trial than anyone, and when both attorneys talked to us afterward, the jury's consensus was 1) that the defendant was the victim and acted in self-defense, and the "victim" should have been prosecuted instead for drawing blood 2) I would have been the foreman.

*that went to mistrial because of "unavailable witness"