“Everybody knows that the dice are loaded.
Everybody rolls with their fingers crossed.
Everybody knows the war is over.
Everybody knows the good guys lost.”
– Leonard Cohen, Everybody Knows
“It is known.” – Dothraki saying
It is not known. Everybody doesn’t know.
When someone claims that everyone knows something, either they are short-cutting and specifically mean ‘everyone in this well-defined small group where complex common knowledge of this particular thing is something we have invested in,’ they are very wrong about how the world works, or much more commonly, they are flat out lying.
Saying that everybody knows is almost never a mistake. The statement isn’t sloppy reasoning. It’s a strategy that aims to cut off discussion or objection, to justify fraud and deception, and to establish truth without evidence.
Not Everybody Knows
Let us first establish quickly that everyone doesn’t know. There are many ways to see this.
One way to see this is to point out that when Alice tells Bob that everybody knows X, either Bob is asserting X because people act as if they don’t know X, or Bob does not know X. That’s why Alice is telling Bob in the first place.
A second way is to attempt to explain something in detail as you would to a child.
A cleaner way is to consider some examples of things that a lot of people don’t know. According to the first Google hit, 32 million American adults can’t read, and 50% can’t read a book at the 8th grade level. Various other tests of basic skills from school don’t look much better. Here are some more basic facts many Americans don’t know, including 20% who think the Sun revolves around the Earth. Nigerian prince scams still make over $700,000 per year. Doctors can’t do basic job-relevant probability calculations within an order of magnitude. Just yesterday (as of writing this) I had to explain to a college graduate that Bitcoin was more volatile than the stock market, and Forex was not a responsible retirement savings plan.
What does the claim that ‘everybody knows’ mean?
There are a few different things ‘everybody knows’ is standing in for when someone claims it.
In most of them, the claim that literal actual ‘everybody knows’ is sort of the Bailey, and the thing we’ll describe here is the implicit Motte that ‘everyone knows’ is your real message. Which of course, in turn, not everybody knows. As is often the case, the Bailey is blatantly false. But demonstrating that is socially costly. It shows you are the one who does not get it, who is not in on the goings on. So much so that when someone ‘calls someone out’ on a blatant lie, the liar socially benefits.
I see four related central modes. They overlap and reinforce each other, and are often all in play at once.
The first central mode is ‘this is obviously true because social proof, so I don’t have to actually provide that social proof.’
Often the proof in question doesn’t exist at all. Other times, it’s a plurality of ‘experts’ in a survey, or a reporter’s reading of a single scientific study, or three friends backing each other up – or people who have been told or gotten the impression everybody knows, so they claim to know, too. The phrase ‘everybody knows’ is a great way to cause an information cascade.
The second central mode of ‘everyone knows’ is when it means ‘if you do not know this, or you question it, you are stupid, ignorant and blameworthy.’
It’s your own damn fault for going out in the rain and getting soaked. It’s your own damn fault for not knowing that everything politicians say (or something the speaker said) is a lie, even though they frequently tell the truth – which means they ‘aren’t really lies’ because no one was fooled. It’s your own damn fault for not keeping up with the latest gossip or fashion trends.
It is made clear that to question this is to show you are stupid, ignorant and blameworthy, especially if the statement everyone knows is false. You’d be all but volunteering to be the scapegoat.
A classic mode is the condemnation ‘everyone knows that X is (everywhere / great / the right thing / necessary / patriotic / fair / standard / appropriate / customary / the party line / how things get done around here / smart / right / a thing / not a thing / a conspiracy theory / wrong / evil / stupid / slander / rhetoric used by the out-group / rhetoric that supports the out-group / unacceptable / impossible / impractical / unthinkable / horrible / unfair / stupid / rude / your own fault / racist / sexist / treason / cheating / cultural appropriation / etc etc etc).
The whole point is to establish truth without allowing a response or providing evidence.
Note that this is self-referencing. To be someone, you have to know what ‘everybody knows’ means.
A third central mode is ‘if you do not know this (and, often, also claim everyone knows this), you do not count as part of everyone, and therefore are no one. If you wish to be someone, or to avoid becoming no one, know this.’
This works both to make those on the outs not people, and to make the statements used unquestionable.
Thus, one is not blameworthy for acting as if everyone knows, because if someone is revealed not to know, that means they are no one, and therefore they have no relevant impact or moral personhood. They can be ignored. Perhaps those who do not know this, or question it, are the outgroup. Perhaps they are simply those who don’t get ahead, the little people. Perhaps they’re just the fools we pity. Regardless, until they catch on, it is good and right to scam them – it is a sin to let a sucker keep his money.
A key variation on this is to flip the order into a way to admonish someone when they expose a falsehood or fraud someone wishes to perpetuate. First they argue that the thing is not a fraud, ideally that everyone knows it is not a fraud, but they lose, they fall back by flipping their position entirely. They now say: You’re calling this thing a fraud. But everyone knows it’s a fraud, so why are you wasting everyone’s time saying it’s a fraud when everyone already knows? This must be a social tactic, trying to lower the status of the fraud by pointing out what everyone already knows. Or if you think we don’t already know, that must mean you think we aren’t anyone. How insulting.
The fourth central mode is ‘we are establishing this as true, and ideally as unquestionable, so pass that information along as something everyone knows.’ It’s aspirational, a self-fulfilling prophecy. Perhaps we already have done so by the time you’re hearing this (and that’s bad, because it means you’re not hearing about new things everyone knows quickly enough!) or perhaps you’re the first person to be told.
Either way, join the conspiracy. Spread that everybody knows the dice are loaded and rolls with their fingers crossed. Spread that everybody knows the war is over, and everybody knows the good guys lost.
So they’ll cross their fingers rather than demand fair dice. So that they’ll stop trying to fight the war.
Echoing the other replies so far, I can think of other practical explanations for saying "everybody knows..." that don't fall into your classification.
1) Everybody knows that presenting a fact X to someone who finds X obvious can sometimes give them the impression that you think they're stupid/uninformed/out-of-touch. For instance, the sentence you just read. For another instance, the first few slides of a scientific talk often present basic facts of the field, e.g. "Proteins comprise one or more chains of amino acids, of which there are 20 natural types." Everybody who's a professional biologist/biochemist/bioinformatician/etc. knows this [1]. If you present this information as being even a little bit novel, you look ridiculous. So a common thing to do is to preface such basic statements of fact with "As is well known / As everybody knows / As I'm sure you know / etc." [2]
No bad faith at all! Just a clarification that your statements are meant to help newcomers or outsiders who may not remember such facts as readily as people who work with them every day.
2) I find myself saying "but everybody knows..." to myself or the person I'm talking to when trying to understand puzzling behavior of others. For example, "everybody knows that if trash bags are left outside the dumpster, bears will come and tear everything up, so why do people keep leaving them there?" In this context, the "everybody knows" clause isn't meant as a literal truth but as a seemingly reasonable hypothesis in tension with concrete evidence to the contrary. If everybody has been told, repeatedly, that trash is to be put in the dumpster and not next to it, why do they act like they don't know this? Obviously there is no real mystery here: people do know, they just don't care enough to put in the effort.
But especially in more complex situations, it often helps to lay out a bunch of reasonable hypotheses and then think about why they might not hold. "Everybody knows ..." is a very common type of reasonable hypothesis and so discussion of this sort will often involve good faith uses of the phrase. Put another way: not all statements that look like facts are meant as facts and in particular, many statements are made expressly for the purpose of tearing them down as an exercise in reasoning (essentially, thinking out loud). But if you're not aware of this dynamic, and it's done too implicitly, it might seem like people are speaking in bad faith.
I guess what I'm trying to say in general is: "this statement of fact is too obviously false to be a mistake" has two possible implications: one, as you say, is that the statement was made in bad faith. The other, though, is that it's not a statement of fact. It's a statement intended to do something more so than to say something.
[1] Of course, even such basic facts aren't even strictly true. There are more than 20 natural amino acids if you include all known species, but, as everybody knows, everybody excludes selenocysteine and pyrrolysine in the canonical list.
[2] The alternative is to exclude these first few slides altogether, but this often makes for a too-abrupt start and the non-specialists are more likely to get lost partway through without those initial reminders of what's what.
In addition to your cases that fail to be explained by the four modes, I submit that Leonard Cohen's song itself also fails to fit. Roughly speaking, one thread of meaning in these verses is that "(approximately) everybody knows the dice are loaded, but they don't raise a fuss because they know if they do, they'll be subjected to an even more unfavorable game." And likewise for the lost war. A second thread of meaning is that, as pjeby pointed out, people want to be at peace with unpleasant things they can't personally change. It's ... (read more)