Hunter gatherers are strongly egalitarian. Sedentary agriculturalists tend to develop hierarchical class structures. The lowest classes tend to be profoundly repressed.
Why so? If we dismiss the usual idiotic ideas based on divine ordination or social Darwinism, what are we left with?
One cardinal fact about the sedentary lifestyle is that it permits much higher birth rates. The higher birth rates mean that societies produce a lot more people than they can feed. In effect, to prevent being torn apart by internecine struggles, societies develop what amounts to a designated dying class. Like the development of organized warfare, another agricultural innovation, having an oppressed class increases the death rate.
At least in large societies, two classes doesn't seem to be enough. Perhaps three or more are needed for stability. Because the upper classes are likely to out reproduce and out survive the lower classes, means for class demotion are also needed. That fear of class demotion, for example, forms a central theme in novels like "Pride and Prejudice" and "War and Peace."
The means to escape the Darwinian jaws of brutal class oppression and war were not really available until quite recently in history. Birth control, even mandatory birth control, seems a lot more humane to me that those alternatives.