It may just be a developmental thing like you said, trying to figure out how to get things open or through things. The other thought is how do you react? Do you try to stop him? Or do you put something in between or open or move what it is he is banging on? He may have learned a way to get you to do something for him...

Matilda used to have tantrums at a young age (9months)where she would throw herself backwards and land on her head & if I didn't react she would keep banging her head on the ground. But hers were definate tantrums & after a few weeks she started walking so we put it down to her wanting to move but not being able too. The tantrums stopped for a while until the next developmental stage came through. They can get frustrated right before a developmental turn so that can encourage it as well. I should say that we were pretty anal before she turned 1 as well & she didn't watch any TV. So not sure if TV would be the influence... it wasn't for her.

Then again... they are all different