I agree that the author and child are both spoiled and undisciplined.

That said, there are plenty of kids today who do not act this way regardless of whether or not they are spanked or regularly threatened with belts. There were also plenty of kids in your era who were spoiled and entitled. They acted horribly toward people, usually the help. Spanking was more common then.

So clearly, whether or not a child gets spanked has little or nothing to do with their behavior or whether they are disciplined.

Spanking is not discipline. Discipline teaches; the root of the word is literally the latin word for “pupil". Spanking is an act revenge or retribution because it happens in response to a transgression; vengeance, vindictive, avenge, revenge all have the same root.

Most of the heavily and effectively disciplined kids I know of were not spanked or threatened with belts. If they were spanked, it was very light seats on the butt when they were toddlers that did not cause pain but startled them back to attention.