Basically people talk about it as if it were stable -- either because they either see it as rooted (this argument has been going on for centuries), or because even if it's fluid, how do you discuss something that is fluid with any sense? Unless you can track and predict the kinds of changes that could occur (so as to define those as well), you lose the ability to define it and thus the point of discussing it.
Personally I don't feel like my personality has "changed". I have had periods in my life where I stretched and pulled and tugged at who I was, to modify myself and improve myself, but once I run out of energy, my personality collapses back towards a particular norm. I have met people in life whose personalities are much more like me, and I have met those with personalities not really like me, in general. And any long term relationships I've had, the people involved still have recognizable personalities even after life changes and the passage of time. My mom is a good example; she still fits super-well under ISFJ generalizations, even after being stretched and expanding over the years to accommodate new ideas. She still has these same basic core principles and approaches. The details change; the core is more recognizable.
I do not view personality as rigid and locked into very specific parameters, but I think there's a general personality style and preference that tends to retain itself. This does mean that even people who share a general "core" style can still look pretty different depending on the particulars of their experience and their current life situation and who they surround themselves by, etc. We all have "preferences." Even our pets have preferences.
EDIT:
I just skimmed over the link. Eh. Seriously? I feel like it's rather a straw man.
LIES WE TELL OURSELVES
- You can categorize personality into “types.â€
- Your personality is ingrained and unchangeable.
- What happened to you in the past determines your personality.
- You have to discover your personality.
- Your personality test results describe who you really are.
These are very vague and broad statements that, even as someone who sees general personality styles as existing, I would have trouble with these statements. Like, these are the kinds of statements that are abusive of type and lead people in the wrong directions.
And then I see this:
Again, a big WHOOPS on the author's part.
I was very much faith-oriented for the first few decades of my life, and even with shared goals and principles among other believers, we still all retained our unique personalities and identities.
Goals are not personality. Goals are conscious decisions about what to pursue. Personality are the tools and traits we use to reach those goals. Sometimes the goals are dependent a bit on our personality -- like, maybe we won't have as a goal to be in charge of a large organization if we are not interested in directing people to start with and making decisions regularly is agonizing. It doesn't mean you don't improve what you can do over the course of life, if there is a need to; but some things are exhausting. I have to make decisions daily in my role as a team lead, but it took me a long time to reach that point of being able to do it (i had to shift my expectations and practice the skills as well), and it still can drain my energy if I have to operate too long in a vacuum.
Also, in my large knowledge of the Bible, I see all of the Bible figures as having distinct personality traits even though they were all supposedly sharing a goal of "following Jesus and/or YHWH". Goals are not personality. Moses and David and Elijah and Ruth were all very different people, this is obvious.
So this guy above changed his goals away from "killing people." That's great. I bet he still goes about not killing people similarly to how he went about killing people; that would be his personality style.
Sooo.... naw. I don't agree with this link. Frankly, it scans as a guy trying to package and sell motivation to readers -- he wants to make a living by convincing them they can do anything and change their lives as they desire. Not a bad message, but first he has to kill all limitations on a person's goals (so let's kill style differences) and he also sees it as an "in" because everyone is very excited to take silly personality tests online nowadays. It's the back door via which he can get inside their heads and sell his ideas. He's just another idea peddler trying to build his business/brand.