Sure, we could talk about the cultural context a bit. Broadly speaking, a cultural context means looking not just at the story and what happens in it, but also examining the time period, society, and location in which it occurs, and how these factors influence the story. It's the difference between looking at just an individual and looking at things like his or her nationality, generation, etc.
This book is set at school, and was published in 1974. This was a time when a huge number of Americans were rebelling against social structures, and when they were concerned with examining the roots of violence (and why we were in Vietnam). Therefore, the violence in this book relates to the larger violence, just as the characters rebelling against teachers is like the generation doing so.