Excellent thread topic,
Santtu! I'm finding the most self-aware replies very interesting.
... And I really wasn't expecting an INTJ reply like
Shaula's.
- I have difficultly taking responsibility for my mistakes and often find ways to blame it on others.
I think I'm getting over this one as I work through my perfectionism (and after having first gotten over my
closed-minded certitude), but warping reality so that I am not at fault is definitely a tendency that I have to watch out for.
... On the plus side (sorry, but it's on-topic re: OP!) this tendency also means I can provide my own
encouraging environment and thus don't need others to help me rationalize my negatives.
^ Case in point.
- I have difficultly initiating projects because I'm afraid of screwing it up. If it isn't perfect then it was a failure.
Yesss!
I used to have an innocence on this score, an arrogant certainty that I could execute any vision I had if I put my mind to it, but now I know that 1) in all visions involving other people there are all sorts of critical factors which are outside my control

and 2) my visions are not as perfect as I once thought.

The combination of these two reality checks was paralyzing for several years and I am only now making baby steps to test my effectiveness after having been humbled by them.
- I'm afraid of uncertainty and try to avoid it as much as possible.
+1. Gray areas and unknowns are stressful to me.
- I become hostile if I loose an argument and arrogant if I win. I hate loosing so much that if I can't win then I'll find a way to take the other person down with me.
Uhh...
I actually think I've all but completely gotten over this one by now though.
- I'm not nearly as caring or humble as I make myself out to be.
Hmm. I don't think I make myself out to be more caring or humble than I really feel, at least not with those in my inner circle. However, it could be that I'm just not very conscious of adapting my persona for public consumption.
(The above doubt applies to RL. I'm quite sure I don't make myself out to be more caring or humble than I really feel here on the board.

)
- I'm very critical and demanding of those who are close to me. I'm constantly trying to influence them that my way is the only right way.
What's that INTJ tagline -
I know a better way?

- I think I'm getting over this*, although not so much out of growth as because influencing (and thereby taking some degree of responsibility for) others has morphed from feeling like a feather in my cap to a burden after becoming aware of 1) and 2) above and hence it's not as often worth the trouble. (It's
easier to be laissez-faire! Who would've thought?

)
* That said, here's
a recent instance of my critical coercion.
- If I've accomplished something I feel proud of and I don't get a lot of feedback I'll 'fish for' compliments and praise.
*spits water on keyboard* Here's
another recent instance.
- I get pretty hard on myself, sometimes self-destructive, if I'm not 'the best'. For some reason I view life like a competition.
I want to disagree with this last one, but considering how often a person in my life has felt the need to tell me that "life is not a zero-sum game", I'm guessing this is instead a problem area that I haven't even begun processing yet.
More negatives, from least to most important:
- I'm prone to comfort eating and seemingly unable to maintain my ideal weight during stressful periods.
- I have a very poor feel for how others perceive me. Even knowing this and consciously seeking feedback, I only pick up on (and correctly interpret) the strongest of signals. Whenever I become aware of a discrepancy in how I thought others viewed me and how they actually view me, I don't know whether to laugh in bemusement (and/or relief) or cry in frustration (and/or embarrassment).
- My conscience is infantile. I hold myself to the standard of doing what is best for me, and so my actions are subject to change according to my whims with total disregard for how other people are affected. Did you take me at my word? Did you expect me to feel today what I felt yesterday? Were you unable to conceive that I would redefine my commitment? I'm so sorry for you!
I have never previously known the self-contempt which the realization of the above has taught me. Examining my actions with input from Ti users who refuse to let me warp reality is what forced the realization upon me. I can only hope that continuing to honestly look myself in the mirror will eventually nurture an integrity of my own.