The main changes that occur with age are an increase in general abilities with experience, a slow decline in strength, and a tendency to look back in time more than forwards. I'd say that none of these things are quadra related, exactly. Not the changes, anyway.

I'd say, though, that the difference between a young and old person being one of looking back vs. looking forward accounts for the association of people who value Si-Te (historical facts, what was, instead of what will be or what is) with old age.

Si-Fe = How we all feel right now.
Se-Ti = External action in a structured context.
Se-Te = External action, any useful facts regardless of context.
Si-Te = What has made me feel this way