Common knowledge
Reasonable People #31: Why the Heard/Depp case dominated the front pages, why a crypto firm paid $14 million to advertise during the Super Bowl, and why video calls are likely to stay annoying
For weeks the legal dispute between Johnny Depp and Amber Heard dominated the news. It was ubiquitous on social media feeds, and endlessly discussed. All this despite the fact that this trial may seem materially irrelevant to our lives1. It doesn’t risk nuclear war or rises in global food prices like war in Ukraine, but on some recent days it has commanded more space on the front pages.
The 2022 Super Bowl took place on February 13. It was watched by around 112 million people, with some companies paying advertising rates of up to $7 million for a 30 second commercial. Coinbase, a cryptocurrency platform, showed a 60 second ad. At over $200,000 a second this is a lot of money to spend to reach an American football audience - not an obvious match for the tech and investment curious market which crypto might appeal to most. Coinbase saved money on the production of the advert, which despite (or because) of its simplicity crashed their servers with a reported 20 million people trying to log onto their website in 1 minute.
Over two years since the first pandemic lockdown - approximately two thousand online meetings later - and video calls are still annoying. I’ve been thinking about this, dear reader, and you’ll be pleased to hear that I have a A Theory as to why. This theory also draws in the mystery of our fascination with Depp/Heard, the $200,000/second cost of Super Bowl ads, why fire alarms are so loud (it isn’t just so you hear them, despite what you think) and the real function of high viz work-wear.
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The thread which connects these things is the idea of Common Knowledge - the things I know, and you know, and everybody knows, and, most importantly, that everybody knows that you and I know.
I could start the newsletter complaining about Depp/Heard because I knew that you’d have heard of the trial, or at least the litigants, and that’s also what makes the circus of their mutual accusations news. Everybody has heard of the protagonists, so it is interesting to hear what they have been up to, not because of the intrinsic merits of the story, but because we care about everybody else and this is an update to the pool of common knowledge.
The Super Bowl audience of 112 million is a good proportion of the US population (331 million), meaning that the event, and adverts shown during it, instantly become common knowledge. Like the royal family in the UK, you might not like it, but it is reasonable to expect you to have some understanding of it. This is the value to advertisers, and particular ones hawking a novel or suspicious product. $14 million is worth it to make your product immediately one everyone has heard of, or feels they should have heard of (and are perhaps missing out on).
And so, video calls. Enjoyable communication has rapport - an ease and fluidity. The foundation for this is knowing that you understand and are understood. In other words, that you share and can update common knowledge through dialogue. The video calls I make are typically utterly adequate in terms of mere communication, but rarely ever good in terms of rapport. The logic of computer audio means you can’t speak simultaneously, that you need to wait to check if you have been heard (and sometimes you haven’t been heard - are you on mute?). The dislocation of everyone’s screens and cameras means gaze is no longer a reliable indicator of what people are looking at, you no longer share a coherent physical space. The timing delays are enough to make things stilted - just ask musicians who will tell you that even the fastest connectivity isn’t good enough to allow playing together over a video call.
The effect is a bit like how sunglasses affect conversation. Maybe in theory all we need to do is speak and hear, but knowing what someone is looking at makes a difference; to hold their gaze, to see they look where you look, or have noticed something you haven’t. Sunglasses don’t stop me seeing, or you seeing, but they stop me seeing what you see - specifically undermining the second order nature of common knowledge (seeing what you see, knowing what you know).
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It’s said that the real purpose of fire alarms is not to alert people, individually, to the risk of fire. It is to create common knowledge that there is a fire alarm. The alarm isn’t just loud so you hear it, but so that everyone knows that everyone else must have heard it. When the fire becomes common knowledge, everyone knows this is a situation which requires you to evacuate. In isolation, this knowledge doesn’t demand action in the same way (recall the diffusion of responsibility experiments where participants saw smoke curling through a vent while confederates had been paid to take no action; Latané & Darley, 1968).
Common knowledge also explains the real value of high viz clothing. Yes, it makes you more visible, so there is a first-order benefit of being seen (and so drivers or whatever won’t hit you by accident), but the real value is the second order effect on common knowledge, everyone knows you are specially highly visible. This allows you to fulfil special roles like blocking traffic, since you have created common knowledge that this is the sort of thing you are equipped to do.
This is why high hiz can be the best clothing if you want to go unnoticed in public (yes you are perceptually more visible, but you may be socially less noticeable as you modify an advertising billboard or, er, whatever you might choose to do in public which isn’t strictly legal but might, on first glance, look like some kind of official maintenance).
You can see common knowledge in our pleasure at call-backs in jokes, or reincorporation in stories. We take pleasure in having our common knowledge, even if only recently established by a narrative, shown to be relevant.
Successful groups and teams rely on their common knowledge to coordinate. It isn’t enough to know that your striker might make a darting run, they need to know that you know so you will mutually recognise the opportunity and make the pass for them to collect. It isn’t enough to trust that the opposite side in a negotiation will keep their word, they need to know that you know they will, otherwise neither of you can rely on the other to value any agreement.
Common knowledge doesn’t have to be true. If we all ‘know’ something that isn’t so it may not matter that it isn’t actually so, since believing that everyone else believes it renders the reality moot. An example is the idea of pluralistic ignorance, where everyone believes they are in the minority on some attitude, and so is inhibited from speaking out. Mistaken common knowledge prevents the very action which could correct the common knowledge about what the consensus is.
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In conclusion, our beliefs and behaviours are influenced by more than what we know - there is a powerful affect of what we know other people know, of our perception of common knowledge. Changing common knowledge may be as critical to persuasion as just changing an individual’s beliefs.
More
Reasonable People #3 - Arguing across common ground, which has some discussion of how the common ground (or lack of it) affects the power of arguments
Latane, B., & Darley, J. M. (1968). Group inhibition of bystander intervention in emergencies. Journal of Personality and Social Psychology, 10(3), 215–221. https://doi.org/10.1037/h0026570
Podcast: YANSS #157 on Pluralistic Ignorance: The psychology behind why people don’t speak out against, and even defend, norms they secretly despise
Paper: The presumed influence of election misinformation on others reduces our own satisfaction with democracy
Relevant to the last edition (RP#30 Quantifying our Faith in reason), where I speculated about how to measure generalised faith in reason - the rationality or whatever of the typical citizen. Nisbet, Mortenson & Li (2021) write:
Pervasive political misinformation threatens the integrity of American electoral democracy but not in the manner most commonly examined. We argue the presumed influence of misinformation (PIM) may be just as pernicious, and widespread, as any direct influence that political misinformation may have on voters. Our online survey of 2,474 respondents in the United States shows that greater attention to political news heightens PIM on others as opposed to oneself, especially among Democrats and Independents. In turn, PIM on others reduces satisfaction with American electoral democracy, eroding the “virtuous circle” between news and democracy, and possibly commitment to democracy in the long-term.
Their question - the one which defined presumed influence of misinformation (PIM) asked about the ‘impact of false or misleading political news stories’ on the self and other voters, in terms of (1) attracting attention; (2) influencing opinion of candidates in the 2020 election (3) influencing voting preferences in 2020 (4) influencing opinion about issues. So, I note, this is a negative charactertisation of rationality (ie surceptibilty to misinformation, not reasonable skepticism, ability to recognise good arguments or other positive aspect of rationality).
Nisbet, E. C., Mortenson, C., & Li, Q. (2021). The presumed influence of election misinformation on others reduces our own satisfaction with democracy. The Harvard Kennedy School Misinformation Review.
PODCAST: YANNS #234 The Truth Wins
David McRaney interviewed me for his podcast, which is released here for patreon-subscribers only. Here’s his blurb:
Deliberation. Debate. Conversation. Though it can feel like that’s what we are doing online as we trade arguments back and forth, most of the places where we currently gather make it much easier to produce arguments in isolation rather than evaluate them together in groups. The latest research suggests we will need much more of the latter if we hope to create a new, modern, functioning marketplace of ideas. In this episode, psychologist Tom Stafford takes us through his research into how to do just that.
I haven’t listened to this myself, but I remember having a great time speaking to David who is a generous and astute interviewer who has been cracking out great podcasts in this area for a while and has a new book (see below) now available for preorder.
Link: YANNS #234: The Truth Wins (subscribe via patreon for the ad free version)
More details on the work with Georgi Karadzhov and Andreas Vlachos is in RP #24: a lens on the magic of deliberation and the preprint
Karadzhov, G., Stafford, T., & Vlachos, A. (2021). DeliData: A dataset for deliberation in multi-party problem solving. arXiv preprint arXiv:2108.05271.
Project website: delibot.xyz
BOOK: How Minds Change: The Surprising Science of Belief, Opinion, and Persuasion by David McRaney
I have a major conflict of interest here. Not only did David just interview me for his podcast, but I think he’s also going to send me a free copy of the book (thanks David!). That said, the reason I am such a huge fan of David’s work is that it is SO GREAT and, if you are reading this newsletter there’s a good chance it is the sort of thing you’ll enjoy. So, I recommend preordering How Minds Change now
I’ll post a detailed review when I get my copy.
Data Viz interlude: psychology research in the UK
The UK Research Excellence Framework is like a general election for research assessment. All UK Universities submit papers, impact case studies and descriptions of their research environment, which are then rated by panels which score them 1 to 4. This is a major opportunity for system-gaming pre-results and for ignoring measurement error once the results are out (if you did well) or bitter complaining (if you didn’t).
The main take away, for me, is that the UK research system supports a huge amount of research, of world leading quality and at world-leading value for money. To visualising this “research power” I made some plots like this, which shows the different instutitions submitting psychology research. The size of each square is proportional to the number of researchers at that University, the colour is according to how highly rated the institutions’s research was (brighter white or yellow is higher, darker reds or grays are lower).
Over 4000 researchers in psychology, psychiatry or neuroscience in the UK. That’s a lot of research!
Code: https://github.com/tomstafford/ref2021
Twitter thread with some more visualisations:
Quick links
You can't A/B test your way out of local optima Sean Taylor’s newsletter on how value is really created by analyzing data (clue: you need a theory, you can’t just iterate small changes)
Mindhacks.com: Chromostereopsis visuali illusion which was new to me and I’ve been playing with
Warning to people doing research via online surveys: Do you know where your survey data come from?
And finally…
“I stated into the abyss” by Tom Gauld for New Scientist
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Comments, questions, typos? Please hit reply or leave a comment up at substack
Edit 2022-06-06: Original “All this despite the fact that, essentially, this trial is irrelevant to our lives”. It has been pointed to me that this line could be read as trivilising domestic abuse and the movement to hold powerful abusers to account. This is not my intent. I do not wish to claim that these topics are irrelevant to our lives, only that celebrity stories as a genre are a news preoccupation beyond the obvious merits of their content, and that they raise the question of why we are concerned with them beyond their material impact on our lives. If I wrote this again, I would pick another celebrity news story and phrase it differently from ‘irrelevant’. Apologies.
Appreciate the footnote. I do think other sections are potentially quite offensive/trivialising too, in terms of the language used. E.g. "the circus of their mutual accusations" and "interesting to hear what they've been up to," and "the mystery of our fascination with Depp/Heard."
Their "mutual accusations", although they may seem like a circus, are unfortunately a product of a commonly used strategy by lawyers and abusers ("darvo") to reverse the victim-offender narrative which is very successful with juries. I think for a lot of people, it's not a mystery that we are following the case, and it's neither fascinating nor interesting to hear what they've been up to - it's very distressing and for many traumatising.