For what reson a person ends up being insesitive?

Answer 1

Ends up? Sometimes people are just that way from the start, but I think a large part is for fear of rejection or other forms of pain. Many have been burnt and have felt betrayed to some degree--their needs or hopes haven't been met, etc. This often leads to bitterness, and if the person isn't careful they let it lead to insensitivity.
Another thing is constant exposure to something which at one point mortifies them, but the more and more they get used to it and it doesn't phase them anymore--like the frog in boiling water analogy (to boil a frog, don't put him in hot water right off--put him in cool water and slowly turn up the heat). I know with movies and such this has been the case for me. However, if I saw any of that on the street, it would phase me . . . but I have to be honest, probably not as much as if I hadn't seen those movies. So repeated exposure is another thing which leads to insensitivity.