Re: Generation starships and their internal society structure
What, you think the majority of people on earth today don't face much the same situation? If you're born to subsistence farmers in South America, India, China, Africa, well, chances are you're going to be a subsistence farmer.
This is why I recommended a feudal state as the model for an on-board society. People don't become unhappy with a lack of social mobility if they are actively discouraged from believing that it's even possible by their society. You'll still get the occasional maverick - it's inevitable, and probably good for societal health - but the end result of that is almost always either a trip to the gallows or getting co-opted by the state.
From our high-freedom society's viewpoint it's less than optimal, but it's also a means to preserve civlization and spread humanity. And with our current technology, the only one we could actually do, and likely to be so for some time to come. I, for one, feel the restriction of some generations to pay for the freedom and survival of future ones is a price worth paying.