Egalitarianism, I'd say (which probably is correlated with trust). In Sweden the switch from the plural ("ni") to the singular ("du") form of you was done quite deliberately, as described in this article:
"The beginning of the du-reformen is associated with Bror Rexed, the then head of the National Board of Health and Welfare (Socialstyrelsen), who in his welcome speech to the staff in 1967 announced that he would address everyone as du, increasing the effects of the reform and bringing it to a more frequent use. The actual reform had started earlier, including the amended language in the major newspaper Dagens Nyheter. It was seen as a reform in a democratic and egalitarian direction.
First, authorities and influential circles tried rehabilitating the Ni in a so-called ni-reform, but most people could not bring themselves to feel civil using that. Then, almost overnight and dubbed the "du reform", the system broke down and du (noted as informal above) became the accepted way of addressing any one person except royalty."
Followup to: Ask and Guess
Ask culture: "I'll be in town this weekend for a business trip. Is it cool if I crash at your place?" Response: “Yes“ or “no”.
Guess culture: "Hey, great news! I'll be in town this weekend for a business trip!" Response: Infer that they might be telling you this because they want something from you, conclude that they might want a place to stay, and offer your hospitality only if you want to. Otherwise, pretend you didn’t infer that.
The two basic rules of Ask Culture: 1) Ask when you want something. 2) Interpret things as requests and feel free to say "no".
The two basic rules of Guess Culture: 1) Ask for things if, and *only* if, you're confident the person will say "yes". 2) Interpret requests as expectations of "yes", and, when possible, avoid saying "no".
Both approaches come with costs and benefits. In the end, I feel pretty strongly that Ask is superior.
But these are not the only two possibilities!
"I'll be in town this weekend for a business trip. I would like to stay at your place, since it would save me the cost of a hotel, plus I would enjoy seeing you and expect we’d have some fun. I'm looking for other options, though, and would rather stay elsewhere than inconvenience you." Response: “I think I need some space this weekend. But I’d love to get a beer or something while you’re in town!” or “You should totally stay with me. I’m looking forward to it.”
There is a third alternative, and I think it's probably what rationalist communities ought to strive for. I call it "Tell Culture".
The two basic rules of Tell Culture: 1) Tell the other person what's going on in your own mind whenever you suspect you'd both benefit from them knowing. (Do NOT assume others will accurately model your mind without your help, or that it will even occur to them to ask you questions to eliminate their ignorance.) 2) Interpret things people tell you as attempts to create common knowledge for shared benefit, rather than as requests or as presumptions of compliance.
Suppose you’re in a conversation that you’re finding aversive, and you can’t figure out why. Your goal is to procure a rain check.
Here are more examples from my own life:
The burden of honesty is even greater in Tell culture than in Ask culture. To a Guess culture person, I imagine much of the above sounds passive aggressive or manipulative, much worse than the rude bluntness of mere Ask. It’s because Guess people aren’t expecting relentless truth-telling, which is exactly what’s necessary here.
If you’re occasionally dishonest and tell people you want things you don't actually care about--like their comfort or convenience--they’ll learn not to trust you, and the inherent freedom of the system will be lost. They’ll learn that you only pretend to care about them to take advantage of their reciprocity instincts, when in fact you’ll count them as having defected if they respond by stating a preference for protecting their own interests.
Tell culture is cooperation with open source codes.
This kind of trust does not develop overnight. Here is the most useful Tell tactic I know of for developing that trust with a native Ask or Guess. It’s saved me sooooo much time and trouble, and I wish I’d thought of it earlier.
"I'm not asking because I expect you to say ‘yes’. I'm asking because I'm having trouble imagining the inside of your head, and I want to understand better. You are completely free to say ‘no’, or to tell me what you’re thinking right now, and I promise it will be fine." It is amazing how often people quickly stop looking shifty and say 'no' after this, or better yet begin to discuss further details.