This test is actually based on the Myers-Briggs personality profile that was all the rave back in the late '70s, early '80s.
I was a rock solid ISTJ then and I'm the same on this little test.
When I was with IBM and MCI, they would make all us managers take the Myers-Briggs and that would determine who we were paired with at the office. Totally BS concept. My boss was an ENFP and I couldn't stand the little prick!