All students should have the chance to be a good influence on others. Provided they are good examples, younger students often look up to older ones, and since middle school students are still close enough in age to relate to young students, they could provide a great deal of help and influence.
When I was in middle school, our school decided we would be mentors to younger students. This was done one time, and never again. I personally enjoyed it, as did the other students. So often we segregate children by age, so they get used to only being friends with the same age group. It's important that young people mix with a good variety of ages, from baby to elderly, and not get stuck into thinking that they should only be friends with people their own age. By mentoring younger children, older children will learn responsibility and that they can have a positive infuence on someone else's life.