Why are older people more sedentary than younger people?  I’m not talking about 70 versus 10.  I’m talking about 20 versus 10, and 30 versus 20, and 40 versus 30 and so on ad infinitum.

As we get older, we become more contemplative, we become quieter, we slow down in every possible manifestation of the phrase.

Why?

I don’t buy that it’s a simple metabolism thing, or the breaking down of our bodies.  Most 28 year olds are in more peak physical condition than most 18 year olds, yet they are LESS likely to listen to loud music at night, LESS likely to be loud and boisterous themselves, and LESS likely to engage in dangerous behaviors (ask your auto insurance company if you don’t believe that one).

There’s also the explanation that our behavior simply becomes more conservative with time.  I think this is slightly closer to the truth, but it still doesn’t answer all the potential questions.

What do you think?