I continue to believe that the Grabby Aliens model rests on an extremely sketchy foundation, namely the anthropic assumption “humanity is randomly-selected out of all intelligent civilizations in the past present and future”.
For one thing, given that the Grabby Aliens model does not weight civilizations by their populations, it follows that, if the Grabby Aliens model is right, then all the “popular” anthropic priors like SIA and SSA and UDASSA and so on are all wrong, IIUC.
For another (related) thing, in order to believe the Grabby Aliens model, we need to make both of the following two claims:
We SHOULD do the following: (1) observe that we (humanity) seem early with respect to all intelligent civilizations that will ever exist; (2) feel surprised at that observation; and then (3) update our credences-about-astrobiology-etc. accordingly;
We SHOULD NOT do the following: (1) observe that we (humanity in 2022) seem early with respect to all humans that will ever exist; (2) feel surprised at that observation; and then (3) update our credences-about-astrobiology-etc. accordingly.
I don’t understand on what grounds somebody could hold both of these opinions simultaneously, but that’s what the Grabby Aliens paper asks us to do. (The second bullet point by the way is the doomsday argument; here’s Robin Hanson’s rationale for rejecting it.)
There was some discussion on this topic at my Question Post “Is Grabby Aliens built on good anthropic reasoning?”. Judge for yourself, but the impression I got from that discussion was that roughly nobody outside the study coauthor was really enthusiastic about the anthropic foundation of the Grabby Aliens model, and that at least one person who had thought the anthropic foundation was fine, turned out to have misunderstood it.
Anyway, this is a review for the LessWrong 2021 review, so I guess the question should be: is this post (and corresponding YouTube video) a “highlight of intellectual progress on this website” (or something along those lines)? Well, I thought it was a lovely and well-crafted YouTube video that faithfully explained the paper. But I also think that it was basically endorsing (or at least, failing to criticize) a paper that is deeply flawed. So I’m strong-voting against including this post in the review, but I’m also upvoting this post itself. :)
UPDATE 2024: I screenshotted this comment on X and Robin Hanson responded: Link.
I continue to believe that the Grabby Aliens model rests on an extremely sketchy foundation, namely the anthropic assumption “humanity is randomly-selected out of all intelligent civilizations in the past present and future”.
For one thing, given that the Grabby Aliens model does not weight civilizations by their populations, it follows that, if the Grabby Aliens model is right, then all the “popular” anthropic priors like SIA and SSA and UDASSA and so on are all wrong, IIUC.
For another (related) thing, in order to believe the Grabby Aliens model, we need to make both of the following two claims:
We SHOULD do the following: (1) observe that we (humanity) seem early with respect to all intelligent civilizations that will ever exist; (2) feel surprised at that observation; and then (3) update our credences-about-astrobiology-etc. accordingly;
We SHOULD NOT do the following: (1) observe that we (humanity in 2022) seem early with respect to all humans that will ever exist; (2) feel surprised at that observation; and then (3) update our credences-about-astrobiology-etc. accordingly.
I don’t understand on what grounds somebody could hold both of these opinions simultaneously, but that’s what the Grabby Aliens paper asks us to do. (The second bullet point by the way is the doomsday argument; here’s Robin Hanson’s rationale for rejecting it.)
There was some discussion on this topic at my Question Post “Is Grabby Aliens built on good anthropic reasoning?”. Judge for yourself, but the impression I got from that discussion was that roughly nobody outside the study coauthor was really enthusiastic about the anthropic foundation of the Grabby Aliens model, and that at least one person who had thought the anthropic foundation was fine, turned out to have misunderstood it.
Anyway, this is a review for the LessWrong 2021 review, so I guess the question should be: is this post (and corresponding YouTube video) a “highlight of intellectual progress on this website” (or something along those lines)? Well, I thought it was a lovely and well-crafted YouTube video that faithfully explained the paper. But I also think that it was basically endorsing (or at least, failing to criticize) a paper that is deeply flawed. So I’m strong-voting against including this post in the review, but I’m also upvoting this post itself. :)
UPDATE 2024: I screenshotted this comment on X and Robin Hanson responded: Link.