I'm 33 years old and been popping in and out of SL for the past 14 years or so, though my account it only 7 years old.
I still remember at the time when I first started playing when I was 18ish, most my friends where 20 to 30 years older then me.
Though since getting back into SL recently, I have yet to be very social in game so can't say if the same is true yet
Been to distracted making my avatars as shiny as possible to even think about being social in a social game PX