My objections would indeed not apply if a new term were used. You can define a new term however you like; that's the point of making a new term. You can't just declare that a commonly used term has a specific meaning without providing some justification for abandoning its other existing meanings.
If I wanted to argue that the definition of "bachelor" is "an unmarried man," I could do so rather easily, by citing this for example. If I were arguing over what counts as "theft," I could offer an argument as to why a particular act should or should not fit under the general definition. An argument like the OP's could theoretically include evidence (of common usage, of confusion, etc.) or argumentation, but the OP's post does not really seem to do this. It declares, "The definition should be X" and then rejects certain usages as not fitting the definition. If you're using an extremely common word like "signaling," you don't get to arbitrarily redefine it.
we're no longer talking about signalling as it was originally conceived.
The word "signal" dates back to the 14th century. The use of the word as a verb dates back to at least the 17th century. The specific meaning you are trying to use seems to have started in the mid-to-late 20th century. That's the issue. Signaling means what you say it means, but it also has a broader meaning. If I do an action that I wouldn't do were it not for the fact that others observe me doing it, it seems very likely that part of my motivation is signaling. The manager clearly qualifies for this, as she would not be "acting decisively" but for the fact that she is being observed. (I also think that Gresham's Law is the wrong one, or that you need a bit of an explanation to tie it into this behaviour, but that's besides the point; the fact that there is a more precise name for a problem does not make that the only name for the problem.).
Unenforceable pre-commitments are still precommitments. If I promise never to cheat on my spouse again, despite a long history of cheating, I've made a commitment. It's not a very credible commitment, but it still belongs in the set labeled, "commitments." If you define "commitment" to only count "credible commitment," you've essentially created a new word.
As with any debate over definitions, this can get circular rather quickly. My point is this: if you want people to use the word "signal" to mean something very specific, and to abandon the conventional use of the word, you need to provide a viable alternative definition, and you need to explain why it would be more productive to abandon the conventional use of the term. I do not think your definition is viable, because it necessarily involves an arbitrary cost threshold. Even if your definition were viable, I don't see how you've shown that there is a problem with the conventional use of the term. Yes, there are different types of signals that differ in important ways, but I don't see why this warrants completely changing how we use the term, rather than specifying weak vs. strong signals.
You've basically come up with four criteria that describe the use of the word "signal" in a highly specific context - traits that exist for pure signalling purposes in evolution or game theory - and then decided, arbitrarily, that this is the one true meaning of "signal." I do not think you have provided adequate evidence or argument to back this claim up.
If everyone around me is a Republican and I am not, it might make sense that I would do things that would signal that I am a Republican, even if these are very cheap and have obvious positive returns. Your definition would not allow this - if it is cheap and has obvious positive returns, it is not "signaling" to you. What you're saying is that if I send a birthday card to a coworker I hate, then I am not "signaling" that I like that person because it's too cheap to send the card.
It may make sense to speak of weak or strong signals, or reliable or unreliable or misleading signals. But you've arbitrarily said that the word applies only when a certain arbitrary threshold is crossed (your 2 and 4).
Incidentally, your theory might actually work if 4 were eliminated and 2 read "the behaviour is more likely to occur if you possess a certain characteristic than if you do not." This would cover my birthday card example - it's cheap, but I'm more likely to do it if I like the person, so it does signal liking the person. But this change would also fix the counter-productive manager. She's doing things that she is more likely to do if she is decisive and in charge. Since she's being evaluated on those criteria, and not "good manager-ness" - which is not generally observable - it would make sense that she would choose to give those signals rather than not. But revising the theory appropriately seems to nullify most or all of your objections.
Tl;dr - rent seeking is bad, m'kay?
This was a interesting read, but it's rather narrowly focused. If Anne were a doctor, then the greater her skill at surgery, the less replaceable she would be. For any occupation, the more skilled a person, the less replaceable she becomes. Replace ability isn't really the relevant metric. Rather, Dr. Anne may have the option to teach other people her surgical skill, increasing her replaceability and reducing theirs. But teaching people a useful skill is obviously altruistic; this doesn't turn on replaceability. Likewise, doing a good job is more altruistic than doing a bad job (when there's no reward). Hence, complex database Anne is less altruistic than friendly database Anne because she's doing her job worse. The reason replaceability isn't discussed is because I don't think it really adds much, especially since one should, generally, act to become more skilled and thus less replaceable.
A simple, interesting, complementary fact is that the cigarette manufacturers all saw profits skyrocket when laws started banning cigarette ads on TV. All of their products are largely interchangeable, so advertising doesn't tell you anything new about the product, it just builds brand loyalty. So it saves everyone costly signalling.
It's also extremely difficult for new cigarette manufacturers to break into the market. It's very hard to use a really clever ad campaign to increase your market share when you're not allowed to advertise on TV. Curiously, this may actually harm consumers, in that it prevents competition from lowering cigarette prices. I suppose this analogizes to the idea that if everyone were suddenly banned from displaying their wealth, it would be very difficult to woo Helen of Troy unless you had clearly shown your wealth prior to the ban. Thus, banning signalling can lead to losses, as the wealthiest suitor may be unable to woo Helen if he came to the game too late.
I don't think this is an adequate rendition of a circular argument. A circular argument is one that contains a conclusion that is identical to a premise; it should in principle be very easy to detect, provided your argument-evaluator is capable of comprehending language efficiently.
"God exists because the Bible says so, and the Bible is the word of God," is circular, because the Bible can't be the word of God unless God exists. This is not actually the argument you evaluate however; the one you evaluate is, "The bible exists and claims to be the word of God; therefore it is more likely that God exists." That argument is not circular (though it is not very strong).
The other argument is just... weirdly phrased. Cloud-trails are caused by things. Significant other evidence suggests those things also have certain properties. We call those things "electrons." There's nothing circular about that. You've just managed to phrase it in an odd manner that is structurally similar to a circular argument by ignoring the vast network of premises that underlies it.
Similarly, slippery slopes simply fail because they don't articulate probabilities or they assign far higher probabilities than are justified by the evidence. "Legalizing marijuana may herald the Apocalypse" is true for certain, extremely small values of "may." If you say it will do so, then your argument should fail because it simply lacks supporting evidence. I'm not sure there's as much action here as you say.
If your point is that there are a lot of people locked up for violating laws that are basically stupid, you're absolutely right.
But that issue is largely irrelevant to the subject of the primary post, which is the accuracy of courts. If the government bans pot, the purpose of evidence law is to determine whether people are guilty of that crime with accuracy.
In other words, your criticism of the normative value of the American legal system is spot-on; we imprison far more people than we should and we have a lot of stupid statutes. But since this context is a discussion of the accuracy of evidentiary rules and court procedure, your criticism is off-topic.
It is self contradictory on its face . Compare these statements:
Literally 100% of people who ever lived have done multiple things which unfriendly legal system might treat as crimes, starting from simple ones like watching youtube videos uploaded without consent of their copyright owners, making mistakes on tax forms, reckless driving, defamation, hate speech, and going as far as the legal system wants to go.
US has extraordinarily high number of prisoners per capita. Looking at crime rates alone, it does not have extraordinarily high levels of serious crime per capita. There's no way most people in prisons can be anything but innocent (or "guilty" of minor and irrelevant "crimes" pretty much everybody is "guilty" of and persecuted on legal system's whims).
Unless you believe that young black men in US are the most criminal group in history of the world, most of them who are in prisons must be innocent by pure statistics.
The first statement provides a complete alternative explanation for the second two. It is entirely possible to believe that (A) there are far too many crimes, (B) police and prosecutors are biased against black people, and this fully explains why there are so many black people in prison without a single one of them needing to be innocent. Similarly, you say that, given crime rates and incarceration rates, some people must be innocent. Again, this is undermined by the fact that you say everyone is guilty of something. You just can't argue that everyone is a criminal, and then argue that high incarceration rates must necessarily be attributable to a high rate of convicting innocent persons. They may both be true, but you have no basis to infer the latter given the former.
To the extent that you disclaim this by saying that people are "guilty" of minor "crimes," your argument becomes largely circular, and is still not supported by evidence. What percentage of thieves/murderers/rapists/etc. are actually caught? How long are sentences? Combine a higher crime rate with a higher catch rate and longer sentences and you easily get a huge prison population without innocent people being convicted. I don't claim to know if this is the case, but you do, so you need to back it up.
There are good reasons to believe few trials that happen are extremely far from any kind of fairness, and they're stacked to give persecution an advantage. Just compare massive funding of police and prosecutors with puny funding of defense attorneys.
You confuse different parts of the justice system, and your criticism is internally self-contradictory. If everyone who ever lived is guilty of something, then high or racially disparate incarceration rates need not catch innocent people. The fact that this occurs is more an indictment of the laws in place and the people who prosecute them, not the courts that adjudicate them.
Put another way, if breathing were a crime, then everyone convicted of it would in fact be guilty. If there were a lot of black men convicted of it, more so than other races, it would likely be due to different rates of prosecution, given how easy the charge would be to prove this is bad, but it is a criticism of the wrong part of the government. It would be like blaming the mayor for the ineffectiveness of the postal service (the former is the city government, the latter is federal).
Edited to clarify: I am referring to the value of our adversarial method and our rules of evidence / constitutional protections - the mechanics of how a trial works. There is an entirely separate issue of prosecutorial discretion and unequal police enforcement and overly draconian laws, which certainly lead to the problems being discussed here. But the entire purpose of evidence law and courtroom proceedings generally is to determine if the person charged is in fact guilty. It is not to determine if the prosecution is charging the right people or if the laws are just or justly enforced. So this criticism seems misplaced.
I echo people's comments about the impropriety of the just-so story.
The analogy is problematic. At best, it proves "there is an possible circumstance where a fairly poorly thought-out instrumentally rational belief is inferior to a true one. Such an example is fundamentally incapable of proving the universal claim that truth is always superior. It's also a bizarre and unrealistic example. On top of that, it actually ends in the optimal outcome.
The actor in the hypothetical likely made the correct utilitarian decision in the terms you assume. The moral thing to do for a drowning person is save them. But if you saved these people, you'd all die anyways. If you don't save them, it seems like they'll almost-drown until they pass out from exhaustion, then drown. Or they'll be killed by the approaching deadly threat. So without more information, there is no realistic possibilitythey survive anyways. This, you actually did the right thing and soared yourself the emotional anguish of making a hard decion.