uh...initial group babble.

if there was one rule to explain how you function in a group setting, it's that you react to what is going on, melding the communication around the people, the context, etc.
You never have the same exact conversation twice, and just like that, you never interact with a group in the exact same way. There may be a set of ideas based on your culture, family, religion, etc. that lead you to believe there are certain ways things should be done. This does not necessarily mean that these rules will be followed everytime, or how carefully they will be followed, or if they will even be thought about it in the group context.
One big factor in a group is how well people know eachother and the relationship you hold with others. In this case, individually, everyone still reacts differently. When I am in a group of people I don't know I become very quiet and tend to observe more. Others feel completly comfortable with the unknown.