Is the test actually taken by 60 year olds, or are the results from when that generation became adults? Because in the former case, it’s expected that their results would be worse. Your cognitive skills decline as you get older, and many people don’t actually use the skills they’ve learned at their jobs, so there is also skill decay due to lack of usage. My mom would have probably been more literate than me when when we were both 20, but probably is not right now.
My point is, you can only make inter-generational comparisons by normalizing for age, say in the 20-30 peak range.
Is the test actually taken by 60 year olds, or are the results from when that generation became adults? Because in the former case, it’s expected that their results would be worse. Your cognitive skills decline as you get older, and many people don’t actually use the skills they’ve learned at their jobs, so there is also skill decay due to lack of usage. My mom would have probably been more literate than me when when we were both 20, but probably is not right now.
My point is, you can only make inter-generational comparisons by normalizing for age, say in the 20-30 peak range.