Well, the well-known formula is "Nature and Nurture" - we are what we are due to genes and environment. This is, of course, huge over-simplification, almost a meme, but it is correct one.
Of course, "genes" does not mean the destiny, even if preferences and abilities are "encoded" there. There are long and boring debate about role of genes and IQ score and the consensus is that "almost everything is inherited but without proper environment, training and fertilizing the potential could not be fully expressed".
Well-off, well-educated parents, in a few generations back, is what could be called the environment. And what it amounts for is not just self-esteem and developed, refined mind, but also non-verbal behavior, which, like looks (a signal of good genes) are much more powerful drive that people like to admit to themselves.
As for ideas of so-called equality, be it socialism or equality between men and women, these are just theories. In reality (at least what we could see in labs) genes are the vehicle of evolution process, which is all about inequality.
It is correct to say that these theories, being intellectually attractive, are in contradiction with the very process which made us. So, it is better to check ones premises.)
For example, people might like it or not, a good-looking person (due to genes) will receive much more attention from people in all his endeavors, be it studying or carer building, or simply having a good time. Too much attention could ruin, and it is well-known in the field of personality disorders.
Please, do not even mention that nonsense that what is considered good-looking varies from culture to culture, from age to age. Good looks are youth, health and lack of deformations ("average" face considered the most beautiful) or signs of good genes.
Actually, any modern psychology textbook treats those subjects is very clear.