I didn't know the terminology so I used descriptive words. Psychometrics is the subset of psychology that looks for conclusions in statistical correlations. If answers to questions X, Y and Z correlate consistently through a number of people, it can be said that those three questions are measuring the same thing. There's a statistical tool to find those correlations. It's called factor analysis.

Anyway, if you make all sorts of questions related to temperament, test them and then make a factor analysis from the results, you'll find that there are five dimensions to human personality (as far as anyone can tell so far). One of them is openness, which on one extreme describes something like being naturally curious and on the other something like being naturally cautious. People high in openness are creative, intuitive and statistically tend towards leftism. People low on openness value tradition, stability, think more logically and tend to dislike change.