My point is, aggregating factors for happiness to find the best country is like aggregating people's favorite colors to find the best color. Each individual's needs and circumstances are unique, and what will make them happy will vary widely as those needs and circumstances vary.
Some interesting (suspect?) findings from the quoted 2023 paper: (2008 - 2017 data)
* Somaliland had the 4th least worries
* Russians were the 7th least angry
* Chinese were the 8th best rested
* Icelanders did great on every metric, but felt very tired (rank 190)
* Venezuelans smiled the 12th most (Panama, Paraguay, Costa Rica did even better)
* Laotians smile the 3rd most, but are also among the angriest (202) !!?
But then I moved to Denmark from that cold place and found myself very happy! Of course circumstances change and a single account means little but I definitely believe some societies lend themselves to greater happiness than others, even in the very developed world.
He appears to have attended the same undergraduate program in Portugal as the MIT professor.
Therefor it seems possible that these shootings were carried out of personal resentment, though only he knew for certain.