This reminded me of a short story I read by the guy that wrote "The Martian" - it's different from what you're describing but in this model there's only one per

This reminded me of a short story I read by the guy that wrote "The Martian" - it's different from what you're describing but in this model there's only one person and they're living every life through reincarnation, with the goal being that you experience all human lives and then you're fully matured and able to move on to whatever the next step is https://en.wikipedia.org/wiki/The_Egg_(Weir_short_story) https://en.wikipedia.org/wiki/The_Egg_(Weir_short_story)