“Our grandfather’s generation, in their prime some 50-75 years ago (for most) were not as tall or as smart by any measure.”
The average Euro-American is shorter today than 150 yrs ago.
http://research.duke.edu/blog/2010/10/getting-shorter-and-fatter
Well, no. The average American is 2 inches taller than then. But the average Euro is 8 inches taller than then.
We haven’t increased our height as much, probably because we were considerably taller than Euros back then.
In WWI multiple people commented on how the rankers in the British Army looked like a different people from the much taller and healthier officers. Malnutrition, probalbly.