The concept of reincarnation may be present in various ideologies, but with regards to the Hindu tradition and South-Asia with which it is most commonly associated, it is - historically speaking - inextricably linked with racism and oppression, rather than any ancient philosophy or theology. Allow me to explain! Hopefully you will find it an interesting example of manipulation through religion, even if slightly irrelevant to the topic
One of my grandmothers is Indian, originally a Hindu belonging to the
Brahmin caste, the highest social class that wields the power of priesthood in Hindu society. As such, it is my own ancestors who were guilty of this crime! When the invaders from the North of India overran the subcontinent, they realised that although the conquered peoples were docile, backward people, the population was much more massive than themselves. Eventually, a generation would arise that would say, "enough is enough!" and they would have an unstoppable tidal wave of rebellion on their hands.
So what did they do... The intelligent people that they were, they began preaching to the people. "God created the Brahmins (priestly class) from his head, the warrior caste from his arms, the business/trading class from his torso, and the labourers ("Untouchable" class) from the feet." They taught that when one dies, if they did a good job where they were, they would be "upgraded", so to speak, in their next life, and this would continue until they were upgraded to and united with God. If you did a bad job, you would be downgraded - and you sure as hell don't want to be downgraded, given the filthy treatment of the Untouchables.
In this way, the lower people of society who formed the LARGEST portion - the servants, the sweepers, the cleaners, the labourers - were subdued and got on with their jobs, propping up the others. They put up with the disrespect and being spat upon by the world, because they craved being "upgraded" eventually, and they accepted that they were who they were because they had been bad in a previous life. It is a crippling, unequal system which not only promotes the rich get richer and the poor get poorer, but
justifies it.