To what extent is this actually true, and to what extent is it just simplistic advice given to people who ought to be advised to leave the person with attribute X just cause it’s pretty likely said person will still be X.
Examples, where X =
Offhand, I’d say pretty often. Changing yourself is difficult. Not impossible, but it requires a type of strength that most people can’t muster up for everything they might want to be different about themselves.
Not only that, but changing other people (especially those who fall into the categories listed in the OP) is damn near impossible. For the case of people who are involved in some way with someone in one of those categories, the advice that they are not going to change is often meant to mean that you can’t change them.
I don’t think you can make an absolute statement about any of those categories – there are definitely people in each of them who have changed. But the chance is small, and unless the person has expressed a willingness to take the necessary steps to change, then leaving them may well be the best option.
I have seen a-holes ( behaviorally) remaining a-holes even after they moved to a higher social strata by wealth acquisition. Despite all the wealth, he could not modify the interaction with others, or learn to shut up when needed.
I have also seen people change for the better, but only in very few cases.
I really agree with Olives. Particularly in areas regarding behavioral and or addiction areas. Also people who are “in the system” be it corrections, mental health or other “systems” will tend to return. Some of it is illness, some of it is past behavior has helped create coping methods that are questionable at best.