The recursion of what most of us call common knowledge is endless: We know that they know that we know that they know, and so on.
No trivial matter, this form of communication is a likely driver of the very development of language so that humans could better coordinate.
So argues Steven Pinker, the public intellectual and Harvard cognitive psychologist, in his new book “When Everyone Knows That Everyone Knows: Common Knowledge and the Mysteries of Money, Power, and Everyday Life.”
Though no specific accusations appear to be public, the timing proved awkward. He’s one of several prominent intellectuals named in a tranche of new correspondence with notorious financier-pedophile Jeffrey Epstein. One of Pinker’s prominent book endorsements is Bill Gates, who is even more exposed.
I read the book before fully understanding this, and it’s not clear what it all means now. Though no great revelation, the book gathers perspective on a widely familiar concept.
Below my notes for future reference.
My notes:
- Private knowledge versus common knowledge (reciprocal knowledge when I know you know but don’t know if you know that I know)
- Mutual knowledge may be better term as common knowledge has a slightly more technical use (as in this book) than in wider use but the author uses common knowledge
- Communication and coordination
- Altruistic (monkeys picking bugs off another’s back) and mutualistic (bird eating bugs off zebra’s back)
- Conventions allow us to coordinate
- Gil Disendruck and Lori Marisol: three year olds that learn a new word assume an adult will know it, but they don’t assume that for new facts
- Michael Chwe’s 2001 book Rational Ritual: social goods are advertised on the Super Bowl (technology consumer products) more than private goods (batteries, breakfast cereal)
- Author cites Erica Chenoweth’s nonviolent stats (challenged by Andreas Malm): 51% vs 25% of nonviolent v violent movements worked, though she acknowledges “the dictators learning curve” – thwarting common knowledge of coordination
- 2013 Justine Sacco tweet: early in RT function nd the idea of virality losing context (irony not understood online) introduced cancel culture
- Truly viral messages feel like common knowledge
- Jillian Jordan et al: social media enforcer of community collective norms (in lieu of courts or even town square floggings) vain in group esteem
- Online “Everyone is both watcher and watched”
- Peter DeScioli and Robert Kurzban: moral condemnation not only signals virtue but also aligns with a dominant faction.
- Some of the norm setting is just to give a focal point to create an identity and community
- Blaming people for outcomes they never intended is a difference between archaic and modern justice
- Darkness at Noon; The Crucible; 1984; The Lottery all showed ritualistic group outing of others to reinforce social standing of others
- Metaphors We Live By book from 1980: idioms help convey common knowledge
- John Geanakoplos: coordination gene “ the upshot is that when coordinating actions, there’s no advantage in sending acknowledgments unless one side feels more vulnerable, or unless the acknowledgment has higher probability of a successful transmission in the previous message” (one-word “Roger” for pilots)
- Mark Twain: “ the trouble with the world is not that people know too little, but that they know so many things that aren’t so”
- Rubenstein’s 1989 electronic mail paradox
- Robert Aumann’s 1976 agreement theorem states that two Bayesian agents with the same prior beliefs cannot “agree to disagree” about the probability of an event if their individual beliefs are common knowledge.
- Tyler Cowen and Hanson: disagreements start with different priors, but same information should get equal treatment
- Good-faith debating: sharing your priors, expressing range of confidence, “steel manning” rather than straw manning and agreeing to adversarial collaborations (what marker would decide) and betting on concrete predictions
- Robert Trivers: people deceive themselves to deceive others
- Alex Tabarrok: bet is a tax on bullshit
- Prisoners dilemma teaches that by giving up something we can gain a better outcome
- Cheap talk and costly signals
- Since the author worked with Paul Bloom in 1990 on the question of why did language evolve, the author now believes the simplest explanation is “language cheaply generates the common knowledge that makes social coordination possible”
- Thomas Schelling: focal point
- Rousseu Stag Hunt
- Wimmer and Perner theory of the mind (three year olds)
- Peter Kinderman and Robin Dunbar: four levels of recursion is the deepest most of us can go easily (he thought, she thought, he thought she thought)
- Dostoevsky and the psychologist Daniel Wagner a century later prove the brain science of the question: can you actively tell your brain to not think of a polar bear?
- “Joint attention” psychologists: this helps children learn culture
- Herbert Clark: common knowledge around a focal point
- Great Barrier Reef annual “sex festival”: the full moon is the focal point
- Curse of knowledge : assume others know what we do
- Keynesian beauty contests and many variations
- Matt Klein on SVB: a bank-run by idiots rather than a bank run by idiots
- Volunteer dilemma: The more bystanders more likely people shirk responsibility
- Ladder of charity: Jewish philosophy
- Why do levels of mutual knowledge affect charitability? From author’s online polling assessing various types of giving: “A donor who gave with common knowledge, had to give twice as much, and a donor with reciprocal knowledge five times as much, to earn the same kudos as a fully private donor. Astonishingly, when it came to the donor who simply made himself known, there was no amount of money he could give – not even 100 times as much – that would make him a charitable in the eyes of our respondent as the anonymous giver.”
- But those who imagined receiving the money just wanted more donations, and didn’t care if the donor was disclosed or not
- His research shows that modern people’s intuition‘s about righteousness, roughly follows the ladder of charity, distinguishing gifts by the opportunities for payback
- David Pinsof social paradox: we show we don’t care and care people know (social judgement and recursive mentalizing)
- Fiske relational models
- Erving Goffman’s Facework
- Martin Daly and Margo Wilson in Homicide: men fight over the common knowledge of whether they are a pushover (in studies, we punish more when others are watching)
- Dominance: I could hurt you
- Status: I could help you
- Richard McAdams using Gillian Hadfield: men and race get locked into dominance by rationally optimizing for most and others playing into lesser outcome — to avoid missing out entirely
- Laughter conveys common knowledge
- Barry O’Neill: Honor, Symbols and War in 1999: leaders engage in 45 geopolitical symbolic acts each year
- On The Origins of War by Donald Kagan: “honor” is a surprisingly high driver of war
- Why Nations Fight by Ned Lebow: interstate wars 1648-2008: the majority were for perceived revenge
- Darwin’s three principles in the evolution of emotional expressions: “serviceable habits” (showing sharp teeth); next “antithesis” (if a dog arching back shows aggression, then showing belly shows submission)
- Three self -conscious emotions
- Embarrassment: public breach of a social norm
- Shame: pubic breach of a moral norm
- (Those two cause blushing but not guilt, which he notes is a costly signal of transgression but only for common knpwwege )
- Irv DeVore: “ if two people anywhere on earth look into each other‘s eyes for more than five seconds, then either they’re going to have sex or one of them is going to kill the other”
- Why off record indirect speech? Plausible deniability of common knowledge
- FIRE: 2000-2024, 1300 scholar punishments
- Brittany Liu and Peter Ditto: we mix up facts and values (war is bad, and so early people didn’t do it)
- “It’s easy to blur the pursuit of objective knowledge with the upholding of moral norms”
- Deplatforning to avoid the creation of common knowledge: “the fear that common knowledge is what makes an idea dangerous helps explain the usual sequence in which a heretic who expresses an idea in a public arena must then be published in a public arena”
- 1973 Noam Chomsky: exploring race and IQ correlation can be ignored because they strengthen the worst elements and are like eye color and intelligence. “Society is happily ‘in ignorance’ of insignificant matters of all sorts”
- John Stuart Mill in On Liberty (1859) has three defenses of unwelcome opinions: it might be true; it might be partially true; or showing why it’s false strengthens what it is true
- Michael Kinsley: a gaffe in Washington is when a politician says something that is true
- “The perils of making private deliberations common knowledge serves as a counterweight to the idea that all the dealings of democratic government must be public as they unfold in real time, and that leaking them is always heroic. “