Still, following on a previous post about the paper "Can Money Buy Happiness? Evidence for European Countries" https://link.springer.com/article/10.1007/s11482-019-09714-3#Sec12 see below a more recent paper on happiness by the renowned David G. Blanchflower professor of Economics at the Darmouth College:
"An early psychology literature suggested there was no age-happiness relationship...No ifs, no buts, well-being is U-shaped in age. The average age at which the U-shaped minimized across the 477 country-level estimates reported here is 48.3. It is in rich and poor countries...Given the robustness of these findings, it remains a puzzle why so many psychologists continue to suggest that well-being is unrelated to age"
