This is the most heartbreaking thing I have seen in a while.
As a Nigerian I am no stranger to corporal punishment, but there is a very clear line after which corporal punishment turns into abuse.
This makes me so angry. Especially the reason the father gave for doing this. So what? Your child doesn't know how old he is. If he doesn't know, tell him. He's only five years old for goodness' sake.
I am convinced this man has a mental problem.
Poor kid. They should be taken away from him and placed with a family that love them for the gifts that they are.
Update: So I was reading the comments on the post, and of course everyone was infuriated at the evil man and his disgusting behaviour, and everything was going so well... until I saw this comment.
Chinese racism never ends does it?