I worked at a school in Castleford, Yorkshire, for eight years teaching maths, but on my pay slip there was a second job: lunchtime supervisor, 1:00 till 1:40, big doors at the end of the maths corridor, every Thursday.
Students weren't allowed on the maths corridor at lunch. Staff were stationed at key points across the building so that students stayed in the social spaces where they were supposed to be, and only returned to subject corridors in the five minutes before afternoon lessons started. My job, while I ate my free sandwich, was to hold that line.
Throughout every lunchtime, students would come up to me with some version of the same request: can I go and get my bag, my coat, my pencil case from whatever room they'd been in that morning. School policy was clear: not without a note in your planner, so I'd apologise and say no, and a few minutes later I'd watch that same student walk out of whichever room it was with their bag, or coat, or pencil case, because they'd gone in from the other end of the corridor where a teacher had said oh yeah, go on then.
That happened every single Thursday, and every single Thursday it did two things.
It made me look mean when I wasn't being mean. I was doing exactly what I was supposed to do. And it made the other teacher look nice when they weren't being nice. They were just ignoring the policy.
I've thought about that corridor a lot over the years, because it contains almost everything I want to say about behaviour in schools.
The problem wasn't the students. They were doing exactly what students do: finding the path of least resistance, trying their luck, going round the obstacle when the obstacle said no. That's not misbehaviour. That's just being twelve.
The problem wasn't me, and it wasn't the teacher at the other end. We were both, in our different ways, trying to be reasonable. One of us just happened to be following the policy and one of us wasn't.
The problem was the gap between what the school said it expected and what actually happened: on a Thursday lunchtime, when no one senior was watching.
That gap is what I call Wishcipline: the distance between a behaviour policy and a behaviour practice. Most schools have the policy. Very few have closed the gap.
Here is what that gap costs, in concrete terms.
It costs the teacher who follows the system their reputation for fairness. Students don't think "the policy says no." They think "Mr Perry said no and the other teacher said yes, so Mr Perry is the strict one." Reputation is currency in a school. Inconsistency spends it on the wrong things.
It costs the student who asked me. They learned that the system is navigable, that no doesn't mean no, it means find a different door. That is a lesson schools teach constantly and mostly without meaning to.
And it costs the school something harder to measure: the shared understanding that expectations apply to everyone, that the rules aren't a matter of which adult you happen to ask.
You don't need consistency in everything. Schools are complicated, students are complicated, and professional judgment matters. But in two or three things — the non-negotiables, the things that make the whole system work — you need every adult in the building doing the same thing, every time, including on a Thursday lunchtime, including the supply teacher, including the lunchtime supervisor eating a free sandwich by the big doors.
Without that, the wrong teachers look mean and the wrong teachers look nice.
The fix isn't a new policy. It's making sure every adult knows what the policy is, why it matters, and what to say when a student asks them to be the teacher at the other end of the corridor.