Quote Originally Posted by machintruc
I know people who can possibly be ISFj. ( acc ; pro )

They can be friendly, but element can make them somewhat assertive, or in certain cases agressive.

For example, my father is possibly a cp6-ISFj ; he tends to be really reckless and capricious, or agressive when his desires not met.

My sister, probably 4-ISFj, is a friendly, modest woman, but his can make her excessively relativistic; In times I insulted her of "progressive hippie", insult which she took somewhat kindly... Socionics taught me that being a F-type is not a weakness, but only a difference.

I think agressivity in ISFj-types is related to information element, but also in belonging to some enneagram categories, especially 6 and 8 ; it can be also related to the RED vMeme.
I didn't think they existed but recently I met an ISFj-4. I related with them much much better than ISFj-6 because of what you said.