As I sit here and write this, my one year old is sitting next to me eating his lunch. We already work on manners and appropriate behavior with him, although his age does not cause me to expect him to be a gentleman at this point. However, we do work on the manners that he does grasp, such as using the American Sign Language Sign for "eat" when he is hungry, as opposed to just screaming until someone gets him what he wants. Does it always work? No, but when he does start yelling, and I know he probably wants food, I will show him food and he will either do the sign or he will mimic me doing it and then I will give him his food in response to that. It is certainly a start in the manners category.