Extremely introverted and extroverted personalities are two ends of a continuum, with most people falling somewhere in between. BUt I people cannot be E people
I people are anxious until a decision point is over but they deal with that by putting off the decision until they have internally worked out all the plan b's. they are then increasingly anxious as the point of decision draws near in case they are late choosing between the plans O people want the decision over and done with so come to the decsion early, and do not want any plan b. They want a 'now' and are prepared to wait until now arrives, until now has arrived.
Anxiety pushes I people inside, to hide until they've gone through it in thought : O people to have it out now and get it behind them. What they think they have aleady said.