I believe I have my whole family correctly typed now, except for my youngest brother. Maybe you all can help. I do havea few ideas what he might be, but I'm going to wait until I hear some of your ideas before I divulge my own.
As a preschooler, he was scared to sleep alone, and so he usually ended up sleeping in my bed with me (since I had a double). He took forever to potty train; doc said he had a physiological developmental delay in this area, though I suspect part of it was just that he often was just "too busy" to bother with going to the bathroom. He continued to have occasional accidents through most of elementary school. And maybe that's too much information, but since it *might* point to Si-devaluing, I decided to bring it up.
He tended to be fairly serious as a kid (serious>merry quadra?). He became more upbeat once he became a teenager (I think he had some self-esteem issues as a younger child). He got picked on some in elementary school.
He was very imaginative in his play. He loved mock sword fights and battles. Medieval weaponry has interested him. In high school, he bought himself a practice bow-and-arrow and set out a stack of hay bales in the backyard for target practice; I don't remember if he was ever very good at it, seems like he didn't actually end up going out there that often. (pointing perhaps to Ne-Ego, being imaginative, coupled with having good ideas and starting to pursue them, but then fizzling out in the follow-through).
He was and is very smart. He is very good at math. We all-- including him-- thought he'd end up majoring in something related to science or engineering, but he's surprised us all by pursuing a degree in English.
He likes to flirt and entertain with little witty remarks and general teasing (Fe-valuing?).
He can be a real goof-ball sometimes, and used to have a really hard time keeping a straight face. When he joined the JROTC in high school, he had to practice keeping a straight face by having my mom and dad and siblings (I was out of the house by then so I didn't get to participate) make silly faces and crack jokes and such to try and get him to smile; he had a really hard time with it at first, but eventually he became quite good at being stoic.
Speaking of JROTC, after two years in the program he advanced to the most senior position available. He even was selected to attend the Naval Academy in Maryland after he graduated high school, and he attended for two years. He has decided not to continue at the Academy, however, in favor of marrying his girlfriend whom he met in Maryland; they have been dating for over a year and he really didn't want to have to wait until he graduated to get married (they do not allow Academy students to marry).
He loves to read, especially Fantasy. Some of his favorite books include Redwall, the books by David Eddings, and The Chronicles of Narnia. He also enjoys playing video games.
Speaking of video games, when he was younger he would be playing a video game, and he would get so mad when something went wrong in the game; he would yell at the screen (Fe?).
He's really good at Dance Dance Revolution
He plays the piano beautifully; everyone in my family plays the piano to some extent, but I believe he is probably the best overall (though my mom is the best sight-reader and fudger of difficult passages lol).
He does not open up easily when it comes to his personal feelings. He does not like to let on that he is sad about something, though he is perfectly ready to "make merry" when the occasion calls for it (merry>serious? or perhaps just weak Fe).