Social stratification exists in every society; it's human nature to classify everything from rocks to humans. The unfortunate side effect of classifying people according to their income, is that we stereotype the lower class as being of less worth than those with greater income. Children who are born into wealthy families are more likely than children born into poverty to enjoy good health, find academic success, succeed in employment and enjoy a long life. Does this mean they're genetically superior, more intelligent or more disciplined workers than those of the lower class? No, wealthier children are just fortunate enough to have the resources: better health care, progressive schooling, etc. It's comparable to the upper class aboard the Titanic who had the opportunity to get on lifeboats first. They were not smarter or more worthy to get off the sinking ship alive, but were fortunate enough to have the financial resources to ride with first class accommodations. .
Education is at least the second most important factor in determining upward mobility. The occupation and educational level of one's parents is the best predictor of one's educational goals and social status. Access to quality education differs by social classes. Many first class people inherit their riches and receive greater educational opportunities. However, our social system supports a wide variety of mechanisms to encourage educational attainment including mandatory school attendance and low cost loans and grants for college students, thus giving everyone a chance to be educated. .
The landmark Coleman Study (1966) found that the single most important factor in determining educational attainment is the family environment. In the United States, the rich dominate our resources. A median family in the U.S. earns $44,467 per year. As Thomas Jefferson said, "Subdividing property so that many, not just the few, have a voice in political affairs, is essential to a healthy democracy".