+1
There has been lots of talk about the mechanics of how different circumstances affect a dwarf's happiness. But a brilliant system of stress factors is irrelevant if it's opaque. The game already has a blizzard of traits and preferences that are presumably interconnected in fascinating ways---except that the players don't understand the connections. So lots of work has gone into a system that the players can't use or appreciate.
There are many other games out there that revolve around keeping vitual citizens happy, and each has to face the same sort of challenge. I hope that the Brothers Adams have looked at some of those games in designing the new stress system. Even though the mechanics of happiness vary widely from game to game, the task of summarizing and presenting the information is pretty much the same every time. Players always ask the same three questions:
1. Why did my person do that? Why did they choose Option A over Option B. In DF, this would mean displaying the numbers on each dwarf's needs for hunger, sleep, socialization, worship, etc. The Sims series, for example, has an elegant system of need bars that show whether your virtual person is likely to seek out food, entertainment, or the bathroom.
2. Why is this person happy or unhappy? DF has some of this now, but it's very indirect and confusing. And, as has already been discussed at great length, the underlying formulas are broken.
3. What's driving the happiness or unhappiness of my people overall? This is OP's point: If several citizens have the same source of unhappiness, then the game needs to combine that data and present it. Do the dwarves need better food, nicer bedrooms, fancier clothes, or more temples? Right now, the game tells you nothing.
To the many players out there: What management-type games do you think do a good job of presenting psychological information?
As to individual diagonosis. I haven't thought about that, but yes, you want to know why this specific dwarf has become haggard and drawn, or what he/she needs. I think yes, it would improve the game, because you'd have an idea of what to do.
I'd like to add that - I think it should be the job of the chief medical dwarf. So not only does the chief medical dwarf fix broken bones and such, he will also do preventive medicine and do something to adress the happiness of the dwarfs.
So when a dwarf becoms haggard or maybe changes a level in happiness, the medical dwarf gets a job "assess happiness", and he goes to the dwarf in question and asks him what the problem is. The quality of the report should depend on his skills. A low skilled dwarf just tells you "not enough recreation", a better diagnosis tells you "not enough prayer, because the unhappy dwarf is constantly mining."
I think it should also be possible to create a job for the medical job to check the happiness of specific dwarfs.
This is, if you want to be able to "protect" an important dwarf, say your legendary armorsmith and really go out on a limb for him. You should be able to get the information about what would make him happier - so you could do something in the game that would achieve this.
As it is, you really just fight in the dark. You give important dwarves a huge bedroom and try to not overwork them and cross fingers. But if you were told "he really needs to eat leopard brain", it would create gameplay.
If i HAD that information, I'd make it a thing to try to get some leopards and butcher them. And it would create a story about my raiding of the elves cauising a huge war - and the beginning of the war was that an armorsmith wanted to eat leopard.
I think the more information you have, the more projects the player would initiate. It would create mini-missions, like when a noble demands more armor stands. Except these missions would be much more variety, and the player would initiate them, which to me is much cooler than getting the (I guess) random noble demands.