"Real provocation" in my above comment would be the sort of "emotional manipulation" that you are talking about.
Conveniently, this makes it impossible to map out any potential emotional manipulation. It's like saying that World War I happened with no real provocation; it was just these random nations snapping towels at each other and somebody got hit in the balls, boo hoo.
Tell me who these hypothetical people are, who flip a switch and kick their neighbor's ass for no reason. Tell me how many months older they are. What competitions did they win recently? What's their relationship to the teachers? How long have they known each other? Why are some of them friends, and others merely classmates? What do they look like, to each other? What are their parents' relationships? What clubs did they join? And so on and so on.
I think you're unnecessarily narrowing the definition of "emotional manipulation".
I also do not know what "real provocation" is and how it differs from "not-real provocation".