No, I referenced folk psychology just to give a sense of the appropriate level of abstraction. I assume that beliefs and desires (etc.) correspond to real (albeit coarse-grained) patterns in people's brains, and so in that sense concern the 'territory' and not just the 'map'. But I take it that these are also not exhaustive of one's total disposition -- human brains also contain a fair bit of 'noise' that the above descriptions fail to capture.
Regardless, this isn't anything to do with signalling, since there's no possibility of manipulated or false belief: it's stipulated that your standing beliefs, desires, etc. are all completely transparent. (And we may also stipulate, in a particular case, that the remaining 'noise' is not something that the agents involved have any changing beliefs about. Let's just say it's common knowledge that the noise leads to unpredictable outcomes in a very small fraction of cases. But don't think of it as the agent building randomness into their source code -- as that would presumably have a folk-psychological analogue. It's more a matter of the firmware being a little unreliable at carrying out the program.)
The upshot, as I see things, is as follows: the vast majority of people who "win" at Newcomb's will be one-boxers. After all, it's precisely the disposition to one-box that is being rewarded. But the predictor (in the variation I'm considering) is not totally omniscient: she can accurately see the patterns in people's brains that correspond to various folk-psychological attributes (beliefs, desires, etc.), but is sometimes confounded by the remaining 'noise'. So it's compatible with having a one-boxing disposition (in the specified sense) that one go on to choose two boxes. And an individual who does this gains the most of all.
(Though obviously one couldn't plan on winning this way, or their disposition would be for two-boxing. But if they have an unexpected and unpredictable 'change of heart' at the moment of decision, my claim is that the resulting decision to two-box is more rather than less rational.)
I still don't see how statements about disposition in your sense are supposed to have an objective truth value (what does someone look like in visually simplified?), and why you think this disposition is supposed to better correlate with peoples predictions about decisions than the non-random component of the decision making process (total disposition) does (or why you think this concept is useful if it doesn't), but I suspect discussing this further won't lead anywhere.
Let's try leaving the disposition discussion aside for a moment: You are postulating ...
A common background assumption on LW seems to be that it's rational to act in accordance with the dispositions one would wish to have. (Rationalists must WIN, and all that.)
E.g., Eliezer:
And more recently, from AdamBell:
Within academic philosophy, this is the position advocated by David Gauthier. Derek Parfit has constructed some compelling counterarguments against Gauthier, so I thought I'd share them here to see what the rest of you think.
First, let's note that there definitely are possible cases where it would be "beneficial to be irrational". For example, suppose an evil demon ('Omega') will scan your brain, assess your rational capacities, and torture you iff you surpass some minimal baseline of rationality. In that case, it would very much be in your interests to fall below the baseline! Or suppose you're rewarded every time you honestly believe the conclusion of some fallacious reasoning. We can easily multiply cases here. What's important for now is just to acknowledge this phenomenon of 'beneficial irrationality' as a genuine possibility.
This possibility poses a problem for the Eliezer-Gauthier methodology. (Quoting Eliezer again:)
The problem, obviously, is that it's possible for irrational agents to receive externally-generated rewards for their dispositions, without this necessarily making their downstream actions any more 'reasonable'. (At this point, you should notice the conflation of 'disposition' and 'choice' in the first quote from Eliezer. Rachel does not envy Irene her choice at all. What she wishes is to have the one-boxer's dispositions, so that the predictor puts a million in the first box, and then to confound all expectations by unpredictably choosing both boxes and reaping the most riches possible.)
To illustrate, consider (a variation on) Parfit's story of the threat-fulfiller and threat-ignorer. Tom has a transparent disposition to fulfill his threats, no matter the cost to himself. So he straps on a bomb, walks up to his neighbour Joe, and threatens to blow them both up unless Joe shines his shoes. Seeing that Tom means business, Joe sensibly gets to work. Not wanting to repeat the experience, Joe later goes and pops a pill to acquire a transparent disposition to ignore threats, no matter the cost to himself. The next day, Tom sees that Joe is now a threat-ignorer, and so leaves him alone.
So far, so good. It seems this threat-ignoring disposition was a great one for Joe to acquire. Until one day... Tom slips up. Due to an unexpected mental glitch, he threatens Joe again. Joe follows his disposition and ignores the threat. BOOM.
Here Joe's final decision seems as disastrously foolish as Tom's slip up. It was good to have the disposition to ignore threats, but that doesn't necessarily make it good idea to act on it. We need to distinguish the desirability of a disposition to X from the rationality of choosing to do X.