INTP and ISFJ All In One — How?

Wow, I haven’t written in a long time! Not that I haven’t wanted to, but because I didn’t have anything interesting to write about. I used to write all the time . . . short stories, creative works. Nothing was ever published, but I had great aspirations. Way back in the day (20 years ago or so), this was my life. Back then, I had taken the Keirsey Temperament Sorter test and turned out to be an INTP. Theoretically, an individual’s temperament doesn’t change throughout life. There’s supposed to be some sort of pre-disposition toward a certain temperament type. There may be characteristic changes within a type, but no type changes, so far as my research has shown.

Fast forward 20 years to today. A few weeks ago, I re-took this test and was surprised to see my type as ISFJ. It was an online test, so I kind of blew it off, thinking there was some mistake in the programming of the site. Yesterday, I bought David Keirsey’s book Please Understand Me II, and re-took the test again. I was ISFJ. So, the test I took online a few weeks back wasn’t wrong after all.

If temperaments are a pre-disposition, how is it that I went from an INTP in my late teen years to an ISFJ today? These are very different temperaments. There are some characteristics that overlap. NTs are geared toward creativity and engineering. I am a software engineer, so that makes a ton of sense. SJs are geared toward accounting, inventory and materials handling, not complex systems. For me, accounting-type jobs are far away from my personal desires. I love programming. I live and breathe complex systems.

Is it possible, then, for a person to have their temperament shaped a lot by life experiences? For example, SJs are the Guardians of society. These folks support the tried and true. Well, that’s not necessarily me. They also are ultra-dependable, to a point of taking on more obligations than they can possibly handle. That’s definitely me. And this is why I’m driven to research this area of my life . . . the “sick sense of responsibility” as someone once described me. Why am I like that? Don’t know.

Is it possible that a person can have two different temperament types overlapping? I don’t mean schizophrenic here. However, I can’t see how a person can go from an NT to an SJ type if temperament is a pre-disposition. Here’s an example. Like I mentioned at the outset of this post, I used to write all the time. Much of my teen years were spent writing stories. I loved it. I still do, but over the years the whole creative side of me just shut down. I can’t think of a single story to write, and I haven’t been able to in a very long time. Not that I don’t want to, I simply can’t. No energy for it as my energies are sapped up in my job, family and other obligations. There hasn’t been a shred of creativity in me in years and years. Yet, I started out that way, and yet, I have the desire to go back to that state of mind. So, at my core, I believe the NT part of me is still there, just somehow repressed, and that life’s experiences have the SJ part of me out in the forefront. Is this even possible? Does this make any sense?