Maybe social forces as well. I don't have the same 'local trust networks' that my parents did for finding someone nearby to do something--probably because I spend most of my time online. And I had more confidence in what I found in the paper Yellow Pages that got delivered to my door than I do in what is presented in an online search, say, for local contractors.

A chain of trust - aka a local village, is not always just the historic medieval village. Often it is just a experience value: I know that guy, i trust his/her judgement when it comes to "topic". So when s/he recommends me a plumber, i know i can trust that guy..

So a chain of trust naturally accumulates over a lifespan- and by the time you will be as old as your dad was at point of reference, you actually would have a chain. Depending of course on the quality of acquaintances. As kid, all you have is your parents and relatives. Some with wild swings. We all had that story telling grandpa whose tall tales we proudly propagated.

Sorry, local village- what was i thinking. Its a chain of entitys (mostly persons) who using there expertise, chain other entities to the chain and thus extend thrust to that entity. A village can hold many chains, but the trust regarding a topic, may only be given to certain parts of those chain networks.