Just speculating here, but if you want to enforce any norms, there must be a way to get rid of the people who refuse to follow them. The question is how, and this depends on the kind of the group.
If the group is something like "people coming to a party I organize", the solution is simply to stop inviting the transgressors. If the group is more like "people living in this village", then you have a problem, because to achieve the same outcome, you would need to exile or kill the transgressors. Which was probably a smaller problem in the past -- if everyone agreed that someone deserves to die, such person simply disappeared one day and no one bothered to investigate how. It is more of a problem today, when the government does not care to protect you efficiently, but suddenly starts paying attention when you take action to protect yourself (because doing so obviously undermines the government's pretext at legitimacy). When the government cares, it can kill people, or "exile" them by putting them in prison.
Okay, I used some harsh words in the previous paragraph. Is "killing (or exiling)" really necessary? Wouldn't a smaller punishment -- such as a fine, or maybe just a concerned frown -- suffice?
I think the answer is: yes it would suffice for most people, but no it wouldn't for some; and you need a clear answer to what happens to those, otherwise your high-trust society still falls apart. If 99% of the population follow the rules but 1% does not, the streets are still littered, homes get broken into, people get raped and murdered. Some people are such that you could fine them out of all the money they have, and they still would keep breaking the rules. So what is the next step here? A civilized solution could be to let them spend their lives in prison. A less civilized solution is to kill them, either officially or unofficially.
So, how do high-trust societies form? At some moment in history, people agree on the rules, and start violently enforcing them. It may be controversial when it happens, but a generation or two later, the rules are simply "how we always do it here". The initial impulse probably comes from a religion or a king (or even from the people, in Switzerland).
How do high-trust societies unravel? When people stop enforcing the rules, for example because the official enforcers of the rules have a conflict of interest, because doing their job properly puts them in bad light somehow (e.g. they get accused of intolerance towards the groups that often break the rules). This naively sounds like diversity is the problem, but the actual problem is when appeasing the diverse groups becomes more important than enforcing the rules. (Singapore is high-trust and diverse.)
Again, this all is just speculation. Historical examples could be very useful, to either support or disprove this.
I'm no historian, but I cannot fit your exiling/killing theory to any recent society I know of.
I know the most about Sweden, so I'll discuss that society. Thinking about Sweden made several things obvious:
- First, an alternative mechanism with similar effect as exiling/killing: simply making the next generation better, and watching the stats improve over time.
- It's not just a question of good norms or correct education, as if these could develop in any direction independent of the government and system in general. Sweden underwent a transformation over many decades of social democracy (1930-1980), and it seems widely accepted now that crime rates went way down because society provided for every last member. Crime is habit-forming, and if no one ever needs to get into the habit, then you get your high-trust society. In fact, I'll add the hypothesis that you don't even need high education nor attempt to directly influence culture.
Removing poverty helps a lot.
But some people are born as psychopaths and no amount of social democracy can change that. What happens to those in Sweden? I assume it's prison if they do something bad, just like at most places.
There are also other mechanisms for making the next generation better, for example forced sterilization.
...perhaps it works best when you do all of this, because different people become criminals for different reasons? Some people are driven to crime by desperate circumstances; some people have low self-control and would also commit crime in Utopia.
Even if something is good, it can be further improved. The question is how, and what is the cost.
There are places where people do not lock their doors. There are places where people leave their bicycles without a lock, and they find them there on their way home. Perhaps we could do even better.
We could do better quantitatively: maybe you trust your neighbors to leave your bike alone, but you wouldn't trust them to leave your purse alone... but it is possible to imagine a society where if someone forgets a banknote in a park, someone will post a message on facebook "hey neighbors, someone forgot some money in the park, if you know who it was please tell them" and the money would stay there until the owner takes it.
We could do better qualitatively: maybe you consider your streets safe enough that no one would hurt you or steal from you... but perhaps you could similarly feel sure that no one will ever hurt you emotionally, or that no business would even take advantage of the information asymmetry.
Finally, high-trust societies can break down, so it is important to understand what keeps them running.
I advice you to be careful with that line of thinking. It may backfire.
I noticed that racism was slowly disappearing precisely until the western world made racism out to be a terrible, terrible crime.
I find that it's precisely the societies with moral policemen telling eachother to be better people which are the least moral.
That it's the communities with the most rules which tend to be the least tolerant, especially when there's multiple rules telling people to be tolerant "or else".
That it's the best and kindest people in the world that hates rules, hates being told what to do, hates telling other people what to do. It's precisely the non-conformists who are the most tolerant and the most open to diversity, and they generally don't like bullying/witch hunting/cancelling people. (That said, it's possible that this type of person is rare, and that the difference is mostly genetic)
You need to arrive at good communities organically, or at least without the use of force. You cannot possibly design a good system and implement it in reality. A community has to regulate itself as it grows, if you try to control it, you will likely make it worse. Tyrannical means can only mask problems, they can't remove them.
If you want an explanation for the above observations, it's likely this: The groups which take things less seriously are less judgmental, less afraid, less cruel and less worried.
I noticed that racism was slowly disappearing precisely until the western world made racism out to be a terrible, terrible crime.
I thought the backlash started when some people turned "anti-racism" into "anti-white racism". Telling people to be "colorblind" didn't have this effect, IMHO. Telling them that "colorblindness" is just another form of racism, did.
Possibly just my opinion; I didn't make a survey, and I am not sure whether people would report truthfully. But from my perspective, if you tell me "if you treat everyone fairly, that's all we expect from you", I am on the board. And if you tell me "you are white, therefore guilty", you have lost me.
I agree that rules often come with a large cost.
That did happen, and at the same time, the ideal of equality was replaced with that of equity. So instead of making things fair and unbiased, people started promoting the opposite kind of unfairness and bias, in order to balance the two. But the psychological driving force behind this tendency is that of revenge. They will go past the balance point if they can, likely saying something along the lines of "Now it's your turn, it's only fair". I wonder if equality or equity will win in the future, they seem mutually exclusive.
I'm also on the side of equality/fairness/neutrality, but I think we're in the minority on that.
In any case, if one takes something seriously enough that they start to fear it, I think all rational thought goes out the window. I've seen the same thing happen with drugs, sexual topics, and mental health, leading to ridiculous myths on all topics. The majority of these myths and flawed understandings only went away 10-20 years ago, before that, the average persons take on them was a complete joke. I think the same goes for a range of different topics today
Just speculating here, but if you want to enforce any norms, there must be a way to get rid of the people who refuse to follow them.
(a.k.a. selective methods)
I don't think violent enforcement is required. But it's at the very least "strict". But this strictness seems to be parents educating their children. Adults living in a village will need eachother, and quickly recognize the value of befriending and helping eachother. If you've lived there 2 or 3 generations, then there's no malicious actions with a positive expected utility available to you.
These factors decrease when the younger generation starts moving to big cities looking for jobs. There's simply too many people there. Besides the places that you go frequently, you will experience that most people are strangers.
Diversity is a problem when the diversity conflicts with the rules. It doesn't matter if you believe in God or Karma as long as the outcome is that you don't steal where theft is illegal. And if you go to a community which is both high-trust and diverse, you should (according to my intuition) find that everyone has lived there for many years already, long enough to come to an understanding and agreement.
Finally, rules are like police. They help enforce the norms of said society, but they're also a symptom that enforcement is needed. It's not the places with the most rules and police which are the safest, nor is it necessarily the ones with the least. When you arrive at a place where rules and police are rarely needed - that's when you know that you've found a good community!
Speculation only!
it seems that high-trust groups are those that have somewhat homogeneous culture, and strong extended-family and local ties. In other words, a lot of social enforcement of norms, with less legible codified behavioral limits.
There can be people who are simultaneously members of high-trust groups and communities, AND low-trust societies and groups.
The important related question, as you say, can this be arrested or mitigated as a group gets larger and more diverse, so social/cultural norm enforcement via "what will grandma think?" becomes infeasible.
I'm unclear why you consider low-trust societies to be natural and require no explanation. To me it makes intuitive sense that small high-trust groups would form naturally at times, and sometimes those groups would, by virtue of cooperation being an advantage, grow over time to be big and successful enough to be classed as "societies".
I picture a high trust situation like a functional family unit or small village where everyone knows everyone, to start. A village a few kilometers away is low trust. Over time, both groups grow, but there's less murdering and thievery and expense spent on various forms of protection against adversarial behaviour in the high-trust group, so they grow faster. Eventually the two villages interact, and some members of the low-trust group defect against their neighbours and help the outsiders to gain some advantage for themselves, while the high trust group operates with a unified goal, such that even if they were similarly sized, the high trust group would be more effective. Net result, the high trust group wins and expands, the low trust group shrinks or is exterminated. More generally, I think in a lot of different forms of competition, the high trust group is going to win because they can coordinate better. So all that is needed is for a high-trust seed to exist in a small functional group, and it may grow to arbitrary size (provided mechanisms for detecting and punishing defectors and free-riders, of course).
I don't claim that this is a well-grounded explanation with the backing of any anthropological research, which is why I'm putting it as a comment rather than an answer. But I do know that children often grow up assuming that whatever environment they grew up in is typical for everyone everywhere. So if a child grows up in a functional family that cooperates with and supports each other, they're going to generalize that and expect others outside of their family to cooperate and support each other was well, unless and until they learn this isn't always the case. This becomes the basis for forming high-trust cooperative relationships with non-kin, where the opportunity exists. Seems to me a high trust society is just one where those small seeds of cooperation have grown to a group of societal size.
Taking it back a step, it seems like we have a lot of instincts that aid us in cooperating with each other. Probably because those with those instincts did better than those without, because a human by itself is puny and weak and can only look in one direction at once and sometimes needs to sleep, but ten humans working together are not subject to those same constraints. And it is those cooperative instincts, like reciprocity, valuing fairness, punishment of defectors, and rewarding generosity with status, which help us easily form trusting cooperative relationships ("easily" relative to how hard it would be if we were fully selfish agents aiming only to maximize some utility function in each interaction, and we further knew that this was true of everyone we interacted with as well), which in turn are the basis for trust within larger-scale groups.
I mean, you're asking this question with the well-founded hope that someone is going to take their own time to give you a good answer, without them being paid to do so or any credible promise of another form of reward. You would be surprised, I think, if the response to this request was an attempt to harm you in order to gain some advantage at your expense. If 10 people with a similar dispositon were trapped on an island for a few generations, you could start a high trust society, could you not?
First, it's clear to me they're not just myths bolstered by propaganda, and they really are qualitatively different from their low-trust counterparts, which I understand, and consider to be "natural," requiring no explanation.
I think it's a different concept than the WEIRD (Western, Educated, Industrialized, Rich, Democratic) thing, though of course, there's a lot of overlap.
A related question: how do they unravel, and can this be arrested?