Question

A child is punished and temporarily stops his or her well-established bad behavior. however, the child soon goes back to acting badly. this is probably because

Answer 1

I believe the answer is: punishment is known only to temporarily suppress or inhibit a behavior
In order to fully change another individuals' behavior, the most effective method is to make the people understand the principle on why they should change it.
For example, for children who like to throw their vegetables, the best method to encourage them to eat it by making them understand how eating the vegetables would make them closer to a figure that they admire (such as super heroes, or cartoon animals)