Just some quick observations from my last fort (44.12), especially regarding intellectual value changing thoughts and their impact on stress:
-The impact of cave adaptation symptoms seems to be huge. Thoughts caused by them frequently led to personality changes. The most common of this changes are related to decorum and stoicism and don't seem to have an impact on stress levels, but others clearly do. Being forced to drink vomit seems to be the worst of the cave adaptation related thoughts potentially leading to high insanity propensity values (in fact, I had about half a dozen of tantruming dwarves over a period of ten years, with most of them being "in a constant state of internal rage" because they were forced to drink vomit). However, some dwarves seem to "harden" trough this kind of thoughts becoming less vulnerable to stress, valuing sacrifice more etc.
-Miasma seems to affect dwarves in a similar way to cave adaptation symptoms, but since my dwarves have been much less exposed to it I can't really tell if there are any significative diferences besides the changes that can occur to the nature value with the "nauseated by the sun" and the like thoughts.
-Another huge personality changer is clothing. Old, tattered and rotting clothes are making my dwarves despise decorum, gripping them with crippling shyness and making some of them find the humor in most situation (among other effects), but this does not seem to have too much of an impact despite the ocassional mortified dwarf cancelling a job. I have a legendary clothesmaker with a monthly schedule for producing clothes, so I guess this could be much worse. Also, my fort is about 220 dwarves so probably just one clothesmaker isn't enough and with more of them it's possible that this kind of thoughts were much less prevalent.
-Justice seems to work in an exemplary way. The family members and friends of a dwarf can take note of a conviction or a expelling and start valuing more things like self control, power or become more nervous etc. Beatings also seem to have a potential effect on the convicted dwarf through the "experienced trauma" thought.
I'm really excited about what others have found about this new link between thoughts and personality values and their impact in our dwarves lifes