The 90-9-1 rule of participation

According to research started more than three decades ago (e.g. Will Hill from Bell Communications Research) on the phenomenon of participation inequality, some "new" conclusions state that from a group of people:

• 1. 90% of users are lurkers (i.e., read or observe, but don't contribute).

• 1. 9% of users contribute from time to time, but other priorities dominate their time.

• 1. 1% of users participate a lot and account for most contributions: it can seem as if they don't have lives because they often post just minutes after whatever event they're commenting on occurs.

Source: Jakob Nielsen’s Alertbox: October 9, 2006; Nielson - Norman Group - 

Participation Inequality: Encouraging More Users to Contribute

This puts in a new light (e.g. numbers) all the interaction one experiences in work meetings, groups he/she is associated to and even among friends. 
Based on this, I believe we usually put on different "hats" according to the environment we're in rather than entirely belonging to one of the groups. For example, in circumstances  we are most familiar with, we tend to contribute, or at least add, to what others are stating (e.g. groups of friends, with old working colleagues). Conversely, the less information we have about a matter and the less outgoing we are as an individual, we tend to act as spectators and seldom give original inputs.  That makes you wonder: 

 - to which group do you belong to in your relevant environments ? 
 - is it ok to belong to that group of participation ? 
     - if yes, when should you reassess this ? 
     - if not, what should you do to re-adjust it ?