I'm not new to this concept, but I was re-reading this edition of the Gita, and this quote hit me in the face, so I will share it with my brethren:
[...] Rightly understood, however, reincarnation is not exotic but quite natural. If personality consists of several sheaths, the body being only the outermost, there is no reason why personality should die when the body is shed. The sages of the Upanishads saw personality as a field of forces. Packets of karma to them are forces that have to work themselves out; if the process is interrupted by death, those forces remain until conditions allow them to work again in a new context.
People seem to inherit the basic elements of their personality genetically. Both good and bad personalities are to reincarnate (appear in subsequent offspring) until their particular varieties die out somehow. Evolution is a process of samsara
(life and death), and reincarnating into a lower being via karma
isn't a wholly-inaccurate concept; we will regress to a dumb ape state if we embrace bad qualities in the human gene pool and keep dumping HIV into our water supply.Samsara
can be good, as it can help to eliminate unwanted elements.
On the flip-side: we can only go higher if we strive for and only accept the best, and not just for ourselves, but for our future selves.