Either way seems beneficial to me. Smoking by myself gives me that extra concentrated focus on reflection that you don't get at school or with people in general. Also, it is obviously great to run the show and do what you want while your high, also, you don't have to share .
However, smoking with friends can be just as fun smoking alone. There's nothing better then planning a smoking day with friends, everyone brining their own herb and bongs/vapes. Inhibitions are lowered and conversation and conciousness is expanded.