I am teaching right now...actually the students are working in groups on a project so I decided to run up to my office rather than pace the classroom, my other alternative (and usual method).
I often wonder about the dynamics of groups - not just the small-ish ones that are working in my class, but the entire cohort, the night class compared to the day class compared to the online course, compared to last semester's, compared to summer session, compared to last year. My night class this semester is so interactive - if I lecture for two sentences - hands are up, questions asked, comments made...if I ask a question there is a field of hands in the air. If we do a group project, during the reporting out session, we barely cover half the material because there is so much discussion.
Then there are cohorts where row after row of students sit there with blank stares, or closed eyes, or fidgeting, hoping to get out five minutes early. What gives, it is the same instructor, similar curriculum, just the times of day and delivery mode differ, and it is never the same cohort that is engaged (sometimes it is the online class, sometimes it is the day class, sometimes it is the night class). I speculated that course size has something to do with it, but that doesn't seem to account for it either. I conclude that peer influences are very powerful. Several engaged students lead and that translates to a good class -- on the other hand, several bored students drag it down and that makes for a poor one.