New each Tuesday. We shouldn't hit our kids. I raised two sons to adulthood without ever needing to really hit them. I thought it was due my good parenting skills. Now I know better.
Some children are simply more accepting of authority.
For a variety of reasons, they are less aggressive and violent than some other children are. I saw an undisciplined four year old bite a daycare worker's arm so hard that she swung her fist around and banged him in the head to make him let go. It worked, but she was appalled that she had reacted by hitting. We really shouldn't hit our kids, but there are limits. I saw another four year old, a really big overweight brute of a boy, abuse the other children daily.