My Personality Type

So in sociology we took a test which determines our personality type. Well, after quite some time we finally got them back.
I've got to say it's intensely accurate.
I'll start with some characteristics of one trait.
Introverts
Like quiet for concentration
Like to think a lot before they act, sometimes without acting.
Work contentedly alone
Have some problems communicating

Here's the overall summary, i'm an INTJ.
Has a very original mind and great amount of drive which he uses only when it pleases him.
In fields which appeal to his imagination, he has fine to power to organize a job or piece of work and carry it through with or without the help of others. He is always skeptical, critical and independent, generally determinded, and often subborn. Can never be driven, seldom led.

I found some more information as well.
-Personal relationships, particularly romantic ones, can be the INTJ's Achilles heel. While they are capable of caring deeply for others (usually a select few), and are willing to spend a great deal of time and effort on a relationship, the knowledge and self-confidence that make them so successful in other areas can suddenly abandon or mislead them in interpersonal situations.

-The emotions of an INTJ are hard to read, and neither male nor female INTJs are apt to express emotional reactions. At times, both will seem cold, reserved, and unresponsive, while in fact INTJs are almost hypersensitive to signals of rejection from those for whom they care

Apparently INTJ is the personality type of masterminds. On one of the worksheets given to us INTJs are described as intellectually ingenious. I'm not so sure about that, I feel I'm not that intelligent.

I'd say most is accurate, besides the whole self-confidence thing. I don't care for some of my traits though. I'm way too stubborn, and I wish I was easier to read. I realize those things at least. What do you think, do you think it's accurate?