A couple of studies in Finland compared people back in 1910 and 1914 with those born about 30 years later. These subjects were tested in person at age 75 and then at 80 with the same battery of physical and cognitive tests. Those born 30 years later had stronger hand grips and stronger lower legs. They had superior verbal fluency and faster reaction times. However, not every kind of measure showed improvements, such as lung function and short-term memory.
The gains that were made appear to be linked to social, behavioral, and economic factors. Education is a pivotal contributor. Better education often leads to higher income, which is associated with better medical care and better nutrition.
REFERENCE
Wallis, C. (2021). Is 70 really the new 60? Scientific American, 324(1), p. 24