After spending the last few months working with strictly 8th graders I find the change from 8th grade to 7th grade to be extremely drastic. The difference in levels of maturity is extremely shocking. Even after 2/3 of the school year has gone by, 7th graders still find it hard to have the rules and procedures of the school locked down. They lack ability to follow rules, and the entire dynamic of the classroom is changed. It is a lot more hand holding and baby-sitting, where as 8th graders had a lot more independence.
8th graders (most of them) can be expected to come into class, pull out their materials and begin writing in their planners. 7th graders on the other hand have to be asked specifically and most of the time don't even bring their materials or planners to class.
7th graders also have a lot more energy, all 30 of them are constantly moving ALL the time. It's a constant struggle to try to watch all 30 of them and keep the classroom running smoothly.
Lets not forget to mention the development differences between 7th and 8th graders. The extreme differences in height are most noticeable. Being 5 foot 5' my 8th graders were often times towering over me, or almost my height. On the other hand my 7th graders range from waist height all the way to being taller than me.The thinking skills and decisions making skills differ greatly in the development of 7th graders as well.
I'm not saying that either is better than the other, what I am saying though is that it is an entirely different style of teaching required to meet the needs of the students. As a teacher, you just hope that you can make it so that the students learn some kind of responsibility or real world problem solving skills during the course of your class so that they become the young adults we want them to be.