For one thing, I think I hadn’t heard of the premortem when I created the term “murphyjitsu” and the basic technique. I do think there’s a slight difference, but it’s minor enough that had I known about premortems then I might have just used that term.
Murphyjitsu showed up as a cute name for a process I had created to pragmatically counter planning fallacy thinking in my own mind. Part of the inspiration was from when Anna and Eliezer had created the “sunk cost kata”, which was more like a bundle of mental tricks for sidestepping sunk cost thinking. As a martial artist, it bugged me that this was what they thought a “rationality kata” was. So in early 2012 I worked pretty hard to offer candidate examples of real rationality katas. Of the… gosh, five or so I created, only two of them proved to be cognitively powerful, and murphyjitsu was the only one that seemed to be teachable.
(The other one was a cognitive kata drawing inspiration from the Crisis of Faith “technique”. I was quite bothered by the fact that the Crisis was something you only really got to practice a rare few times in your life, so how could you possibly be good at it when the time comes? So I found ways to train sub-skills and chain them together, much like a martial arts kata… and ripped several old family religious beliefs out of me along the way. I was never able to convey how to do this to anyone else though.)
If I remember right, I introduced murphyjitsu in an early CFAR class on the planning fallacy. It’s worth noticing that premortem and murphyjitsu aren’t calibrated debiasing techniques: you’re basically adding pessimism to counter overoptimism, instead of aiming for truth. Outside view reasoning is closer to a calibrated debiasing move here. So if you’re just trying to get the right number for how long something is going to take, you wouldn’t want to rely on murphyjitsu or premortem. Just reference class forecast that sucker.
But I also wanted to encourage action effectiveness. One of my major concerns coming into the rationality community was the serious amount of disembodiment I was seeing. Getting time estimates right doesn’t matter if it doesn’t move your hands and feet. Knowing theories about diet & exercise doesn’t matter if you don’t enact them. Etc.
So the point of murphyjitsu was to blend helpful pessimism with a drive to do something about the likely future difficulties.
That’s the main flavor difference I see between murphyjitsu and premortem. The latter can be a predicative tool to decide whether the action is worth taking. The former has more of a martial arts flavor, like seeing the future problem coming for you and then you counterstrike it. (Take that, Murphy!)
But yes, of course, one could argue that’s part of the intent of the premortem anyway. Sure.
I do think it’s telling that the name still sticks around ten years later. Flavor/vibe differences matter.
I invented the term. I can speak to this.
For one thing, I think I hadn’t heard of the premortem when I created the term “murphyjitsu” and the basic technique. I do think there’s a slight difference, but it’s minor enough that had I known about premortems then I might have just used that term.
Murphyjitsu showed up as a cute name for a process I had created to pragmatically counter planning fallacy thinking in my own mind. Part of the inspiration was from when Anna and Eliezer had created the “sunk cost kata”, which was more like a bundle of mental tricks for sidestepping sunk cost thinking. As a martial artist, it bugged me that this was what they thought a “rationality kata” was. So in early 2012 I worked pretty hard to offer candidate examples of real rationality katas. Of the… gosh, five or so I created, only two of them proved to be cognitively powerful, and murphyjitsu was the only one that seemed to be teachable.
(The other one was a cognitive kata drawing inspiration from the Crisis of Faith “technique”. I was quite bothered by the fact that the Crisis was something you only really got to practice a rare few times in your life, so how could you possibly be good at it when the time comes? So I found ways to train sub-skills and chain them together, much like a martial arts kata… and ripped several old family religious beliefs out of me along the way. I was never able to convey how to do this to anyone else though.)
If I remember right, I introduced murphyjitsu in an early CFAR class on the planning fallacy. It’s worth noticing that premortem and murphyjitsu aren’t calibrated debiasing techniques: you’re basically adding pessimism to counter overoptimism, instead of aiming for truth. Outside view reasoning is closer to a calibrated debiasing move here. So if you’re just trying to get the right number for how long something is going to take, you wouldn’t want to rely on murphyjitsu or premortem. Just reference class forecast that sucker.
But I also wanted to encourage action effectiveness. One of my major concerns coming into the rationality community was the serious amount of disembodiment I was seeing. Getting time estimates right doesn’t matter if it doesn’t move your hands and feet. Knowing theories about diet & exercise doesn’t matter if you don’t enact them. Etc.
So the point of murphyjitsu was to blend helpful pessimism with a drive to do something about the likely future difficulties.
That’s the main flavor difference I see between murphyjitsu and premortem. The latter can be a predicative tool to decide whether the action is worth taking. The former has more of a martial arts flavor, like seeing the future problem coming for you and then you counterstrike it. (Take that, Murphy!)
But yes, of course, one could argue that’s part of the intent of the premortem anyway. Sure.
I do think it’s telling that the name still sticks around ten years later. Flavor/vibe differences matter.