Ian, you make a valuable point. As anyone who has taken the Myers Briggs knows, some of us are introverts and some are extroverts. And some approach tasks with a "just do it" attitude while others say, "let me sleep on it." Online dialogue has the flexibility to work for either style.
To take it a step further, while online text-based dialogue lacks the visual cues, at the same time we take race, age, gender, attractiveness, accents etc. out of the equation. When we dialogue online we do not know who is participating via an assistive technology device, and who is sitting in a wheelchair. Whether we are aware of these characteristics or not, online we truly judge each other by the content of our characters, as demonstrated by the respect we show for all contributions of thoughts and ideas. Going back to earlier posts about trust and collaboration: the important thing is whether I can trust you to be honest with me, fair, and reliable.
Janet