My son is 16 months. We have a clamp on seat for the bar counter that he eats in. When he is done he whips his head back, banging it on the back of the seat. He does it very hard and will do it over and over until we get him out. Sometimes he does it with a little smile on his face, sometimes he starts crying. He's been doing this for quite some time. He has also now started banging his head on the floor or on the wall. If I take something away from him, he gets mad goes down on the floor and bangs his head once or twice or walks over to a wall and bangs his head. Is this considered a normal behaviour?
The other thing he does which I think is a comfort thing is pinch at his own neck. If he's in my arms or in bed with me he tries to pinch at my neck but I remove his hand, he tries again, I remove his hand and then he starts pinching at his own neck. He does it all the time though, when he's playing, walking around... Would you consider this a comfort thing?