I agree with you, Sassy Frassy. I work in an incredibly deprived area and we have BIG behaviour problems borne out of emotional instability, chaotic homelives and anger problems. However, the behaviour problems are deep seated emotional problems and, as such, we tend to have big blow ups from children who have lost control of their tempers instead of low level disruption. The low level stuff is the children choosing to behave in a disruptive manner and we have a very clear policy (down to a list on the wall of every room of the exact consquence for each behaviour, so that everyone knows the result of shouting out, talking too loudly, getting out of their seat without permission, throwing things...etc). As a result, we don't have too much of that and when it arises it is dealt with swiftly and firmly. You are right - it is about expectations.
Being spat at, scratched, kicked and sworn at by children who have completely lost control of themselves because they were beaten black and blue by Dad last week, or their Mum has just gone to prison, yes. We get quite a bit of that, but that takes a lot of time and support and nurturing to solve.
I'd love to teach at that school. I think I'd be able to engage those children and get them working - it has made me feel a whole lot better. (I do understand that it was heavily edited, by the way) If that is the worst behaviour they have then it would be a walk in the park for any teacher at my school!