That said, we MUST consider the social and emotional development stages of our students as an age cohort.
Eighth graders love to talk.
Instead of fighting that, use it to your advantage. Provide plenty of opportunities where they can work in small groups and talk. Recognize that you will need to weave in and among the groups to redirect pure socializing to academic discussion, and accept that that is part of teaching eighth graders. IF you provide those opportunities, then your students will be more likely to respond positively on the relatively rare occasions when you need to talk to them as a whole group. Minimize those occasions to the absolute fewest, because they are difficult to manage, as eighth graders' natural tendency is to chat and socialize with peers.