To find answer to this question, we should take a look at research done my Abraham Maslow in 1943 about hiearchy of needs [1].
Now compare those needs to this research done by Forrester research about user roles in social media [2]:
If you compare each of the steps of the ladder to each levels of the pyramid, you may notice that it goes suprisingly 1 on 1. This would mean that we act in online almost as we would act in normal life - our needs determine our actions.
What do you think? Are these two researches comparable?
I say yes
[1]http://en.wikipedia.org/wiki/Maslow%27s_hierarchy_of_needs
[2]http://forrester.typepad.com/groundswell/2007/04/forresters_new_.html