A cross posting (edited) from a discussion in the casteless community in orkut:
Everything that's accumulated by means of capabilities will have a tendency to accumulate unevenly. Take the simple example of money. In a purely capitalistic society, even if we start with an initial condition of hypothetical fair competition, the more capable ones will soon march ahead of others. Then, when that generation passes away, they will always tend to bequeath their wealth to the people they consider as their offsprings, and heirs. Therefore, from the very next generation, people will start their lives (read 'races') from varying degrees of advantage. Over several generations, this difference will have a natural tendency to widen leading to plutocracy, oligarchy, aristocracy, and finally feudalism.
This is true for all valuable things : money, power, social status and even knowledge. Casteism is culmination of intellectual and social aristocracy.
Casteism exists in various disguises in our society. The evil of casteism is much deeper rooted than the archetypal 'casteism' that we usually talk about. Getting rid of casteism in a true sense would mean that people must bequeath their earnings and wealth (whether of currency, power, knowledge etc) to those they consider worthy heirs of it, not to those who are their natural offsprings.
Not at all easy because of many reasons. One hurdle is that we are hardwired to be biased to our biological offsprings. Not obeying that is hard. Not commenting about its rightness or wrongness. But each act done against the dictate of nature creates an added element of tension. We have still done many such things and have succeeded. I am hopeful even this can be achieved. But it's quite tough. Another hurdle is, doing so, it may have unpredictable consequences on social structures like family, which, otherwise have proven rather effective, and again come to us through our biology.
But as a good start, let's try and understand the problem of casteism and class-feelings in its entirety. Let's not hurry to promise to get rid of them.