ISTps, 2 of them, both guys... They both try to seem very unique, they don't believe in tests, they listen to (or have listened to in some point) Tiamat and other kinds of heavy music. They are very sure that they are always right. They sometimes are, but not like I would ever tell them that. They are rather phlegmatic, but in an aggressive way. They always have the look that they are thinking about evil things. So if you meet them, they will probably be rather reserved, they won't show much body-language, they seem to have strong eyebrows, because they keep glaring at the world. When you argue with them, they will tell you why they are right and if you try to prove them wrong, they'll get very mean. They won't even try to argue, they'll just tell you "you're wrong. you don't know enough to argue". They will never admit that they were wrong and they are not very willing to compromise. They are mean misanthropic people who don't even try to hide that they hate most people. And they really do go "Muahahahaaaaa".

ISTjs, two of them, both girls: They are more positive, compared to ISTps. From another post, written by me: "I know a couple of ISTjs and they are very similar. They even look similar in a way. Both wear rather gray not-outstanding clothes, glasses, no make-up, are cum laude students, short, friendly and most importantly - both are selectively opinionated. They are not very original in their thoughts, but they are intelligent in a logical way (rather analytical, not sharp and witty)." They also think they are right most of the time, but they are willing to explain their thoughts. If you still don't agree, they might say, "This is clear evidence, how can't you see I'm right?!". They won't be judgemental about it. Also, they are very strict about details in everything that they do. True perfectionists. They will suck it up, if others pay no attention to details and their life isn't influenced by it. They are rather positive people, but they rarely show it. They worry a lot and they will do something about it. When they worry about an exam, they will spend A LOT of time studying.

And how to see the difference... ISTps are evil, ISTjs are shy. ISTps thinks that everyone else is wrong, ISTjs just think that they themselves are right. ISTps try to give the impression that nothing can influence them, because they are so special, but are really VERY easy to offend. Then they will treat you as a life-long enemy. ISTjs on the other hand give no first impression at all, so it looks like they are very easy to influence, but they are much stronger inside. They are not very easy to offend. If you say the wrong thing, they will rather angry than offended. They might not even take it personally.