In some theologies if one has passed through all the trials and tribulations necessary to become a human (their karma is that good) then they find themselves in a hallway full of couples having sex. They choose one of these to be their parents. At the end of the hall is a light and passing through that they become reincarnated.
Assume this is accurate. (This must be done for the sake of argument because otherwise we have nothing to talk about.)
First, not all sex is good. Not by a long shot. Some souls must see horrifying things and of those some must decide, "That's who I want my parents to be." Second, it means that rich people choose to be rich and poor people choose to be poor.
Now, think about that. What kind of a person says, "I want to live in the lap of luxury being spoiled rotten and never having to work a day in my life," and what kind of person says, "See that poor woman who's obviously going end up as a single mother because look at what that bastard is doing to her? I'll live in abject poverty with her in hopes that I can bring some joy to her life"?
When you think about it, doesn't it seem like those born rich must have been those who barely made the cut and were almost restricted to being baboons (these theologies tend to say that being a human is the best) while those who are born poor must be the most compassionate souls of the lot?