I don't even know what the law of reciprocals is. I would have to look it up on Google first.
I just read your response and if you are talking about the law that "what goes around comes around", I would say just that. Perhaps there is some metaphysical explanation to this phenomenon or maybe it's due to Divine order, but that I can not say as I am not God nor have I studied metaphysics. However, I guess my original answer still applies that is "Google search".