Wikipedia has a nice brief overview of the idea of the hidden curriculum:
When I first arrived at my new school and got my classroom, it took me several days to figure out why I felt so depressed whenever I unlocked my classroom. It was only after about a day of taking down the previous occupant's wall hangings that it hit me: everything hanging up was about rules, schedules, and basic skills. Without saying so explicitly in words, it all said, "I the teacher am more concerned with managing your behavior than I am with inspiring your learning." It said, "I too am counting the minutes until the end-of-day bell rings."
It was a big "Ouch" moment.
Now teachers don't do this because they are bad people or boring people. It is simply a conditioned habit of teaching behavior. It's a trance (or a ditch) we've fallen into. But as my mentor always says, "Noticing shifts the energy." And once I've noticed it, I can address it.
So I made a radical U-turn in my classroom design and decorating philosophy. As much as it bothers me to have disorganized shelves and messy cabinets, this both more urgent AND more important:
In my classroom, I want students to be focused on things that are both urgent AND important.
I'll add some pictures later but I wanted to get these thoughts down. In the meantime, I'm wondering, what unspoken curriculum is being emphasized in your classroom?