One of my most-confident guesses about anthropics is that being multiply-instantiated in other ways is analogous. For instance, if there are two identical physical copies of you (in physical rooms that are identical enough that you’re going to make the same observations for the length of the hypothetical, etc.), then my guess is that there isn’t a real question about which one is you. They are both you. You are the pattern, not the meat.
Thinking about identical brains as the same person is an interesting idea, and I think it’s useful for reasoning about some decision puzzles.
To anyone thinking about this idea, it has some important limitations. Don’t try to use it in domains where counting the number of individuals/observers is important. If you roll a die 100 times and it keeps coming up “6” then you should update towards it being a loaded die, even though there are infinite copies of every brain state experiencing every possibility of the die rolls. If you’re in a trolley problem where the five people on the track have identical brains, you should still pull the lever, or else utilitarian ethics don’t work (and if you’re going to bite the bullet that utilitarian ethics don’t work because of this, you have to also bite the bullet on reasoning about the world from your own observations not working, which it obviously does).
Thinking about identical brains as the same person is an interesting idea, and I think it’s useful for reasoning about some decision puzzles.
To anyone thinking about this idea, it has some important limitations. Don’t try to use it in domains where counting the number of individuals/observers is important. If you roll a die 100 times and it keeps coming up “6” then you should update towards it being a loaded die, even though there are infinite copies of every brain state experiencing every possibility of the die rolls. If you’re in a trolley problem where the five people on the track have identical brains, you should still pull the lever, or else utilitarian ethics don’t work (and if you’re going to bite the bullet that utilitarian ethics don’t work because of this, you have to also bite the bullet on reasoning about the world from your own observations not working, which it obviously does).
Here’s a Bostrom paper talking about this https://nickbostrom.com/papers/experience.pdf