Writes the economics professor Gregory Clark, in a NYT piece titled "Your Ancestors, Your Fate."
Go to the link to scrutinize the scrutiny under which the alternative explanation did not hold up. If the not holding up holds up, consider Clark's conclusion:
As the political theorist John Rawls suggested in his landmark work “A Theory of Justice” (1971), innate differences in talent and drive mean that, to create a fair society, the disadvantages of low social status should be limited. We are not suggesting that the fact of slow mobility means that policies to lift up the lives of the disadvantaged are for naught — quite the opposite. Sweden is, for the less well off, a better place to live than the United States, and that is a good thing. And opportunities for people to flourish to the best of their abilities are essential.
Large-scale, rapid social mobility is impossible to legislate. What governments can do is ameliorate the effects of life’s inherent unfairness. Where we will fall within the social spectrum is largely fated at birth. Given that fact, we have to decide how much reward, or punishment, should be attached to what is ultimately fickle and arbitrary, the lottery of your lineage.