This thread is just weird. A little bit disturbing.
A 6-year-old doesn't even have a good grasp on the world around him, how is he supposed to photograph it? He doesn't have full motor skill development, or the cognitive ability to even understand what photography means. You're pushing your hobby on him, and before you tell me "he likes it" have you thought that 6-year olds are incredibly impressionable, and anything he sees you do (and then you proceed to put in his hands), he will seem to like? Does this mean that he is enjoying it for what it is? No.
I'm sure you have the best of intentions (photography brings you great joy, and you'd like to see your children experience that too), but let him be a kid, and find his hobbies on his own (better yet, let him experience that period of childhood where he just plays, not even having hobbies) . It'll be that much more rewarding when he gets somewhere himself.