I'll be honest - I am rather confident with my typing as INFJ. I have always tested INFJ (in the past, with low J preferences, and now, with higher J and lower N preferences - I attribute that to attempting to develop a more mature view of things as I have moved on into the professional world).
However I don't really understand my extroversion/introversion tendencies. My E/I ratio tends to fluctuate due to the way tests are written. If they are written with the assumption that extroverts want to be around more people, more often, then I test high on introversion. If they assume that extroverts often start conversations, and like to talk, be a part of, and get involved when they are around others, I may get a very low score with introversion (However, generally not enough to be considered an extrovert).
Why does this phenomenon happen? I generally avoid people and social events to a degree that most would call me a recluse. I stay at home and don't like to get out much. Social gatherings exhaust me and I don't understand how some people (like my brother) can be around people ALL THE TIME. However, when I am a part of said social gatherings (often not by choice), I can go as far as to initiate conversation (though I usually am rather talkative as a receiver and listener), get things going, push people to action. I also am highly optimistic and enjoy making jokes. (I am also often this way on the internet, partially because people respond better to me and I don't get exhausted nearly as easily.)
I think the reason that I am talkative in social situations is that I am attempting to use my "extroversion" to control and order people with my Judging side. I want to get things going, so I take it upon myself sometimes to motivate people to action. Also, I think it might be that I am trying to gather information about them by pushing them to reveal themselves, as well. Especially with introverts, I have noticed that I automatically nudge them to participate, even individually sometimes. I will sometimes call someone out if they aren't participating. Also, my Judging side gets even stronger when I am around predominantly Perceiving people. I am a freelance artist who often works with other artists, and I frequently feel like I have to match my Perceiving boss's ratio. I fix his spelling and grammar errors, encourage him to make progress, etc... His motto may be "We need to make some progress every time we meet" but I feel like he needs to expand it to "We need to make some WORTHWHILE progress every time we meet." It can get frustrating for me working with people who are slower to make decisions and move forward.
Is my insight into this completely crazy? I have considered it for a while and it makes sense to me, however, I am curious as to whether it makes sense to others who may be more experienced with this material than I am.