Catherine,
Go watch the video, NOT THE GIF.
http://www.youtube.com/watch?v=XMIhL63KPxw
The kid did NOTHING wrong. He was being attacked by the cat.
His mom should have swatted the cat.
Since the mom was not protecting her son, the boy did what he needed to to protect himself. The cat needed the punch in the head it got.
You don’t discipline cats by “punching them in the head.”
Please. Don’t ever get a cat. Nor any pet, for that matter.