It seems like, in middle school, most kids are in that immature mindset of "oh, I'm in middle school now, I'm cool" or "Imma gonna show my place in school" or "I'm almost in high school, hooray for teenage drama! I get excitement in my life". So, there is much more drama and, surprisingly, violence in middle schools because of all of the fights and stupid shit that goes on, which little middle schoolers think is "cool".
I don't know for sure, but it could possibly be that in middle school, you're trying hard to me mature, but you're still young, so you don't know how to be mature, exactly. Which leads to the stupid drama and fights and constant swearing, because that's "what adults do."
Will-powered Spriter, I believe it's just your school (or area), not High Schools in general. I know that a great deal of people at my High School (mostly Seniors, understandably so) are generally more mature. Now, if you take a look at the Freshmen and Sophomores...
Eew. Sophomores. I thought Freshmen were annoying (which, I suppose, they are) to the average non-Freshman High School student (and to the occasional open-eyed Freshman), but Sophomores... they're the worst. They think they're so awesome because they aren't Freshmen anymore, like they can rule the schools or something. They boss Freshmen around and pretend to have all this maturity and power... they're like the middle schoolers of High School.