I'm certainly more innovative when it's the opposite. When you're all on the same page from the beginning and you're deliberating in that way, you will often end up following a very narrow path. Divergence and ideation happens when you're given an initial problem and you attempt to solve said problem independently. THEN you come together and you can start to fashion together a solution, synthesizing the best parts of each solution. Even if someone is completely off the mark with the rest of the group, their lack of initial perspective can bring greater rewards in the long run as they've got a fresher mind to attack the problem from a different angle.

Ah! The myth of "It got invented at a water cool chat" thing. I tend to agree to this one, as I was talking more about informal chatting (like about the last vacation, maybe sharing restaurant suggestions, talking about the boss doing bossy things and so on), which in turn would enable some kind of bonding between people.

I'd appreciate some links