Vertical writing is that of people who try to remain logical, less so that those who are afraid to show emotion.  For them, they value logic not as a distraction from interpersonal relationships, but rather for the nobility of logic.

These people tend to get along with the most people, but may harbor some preference for others like them.  They don't require others to acknowledge their emotions, nor spend much energy on suppressing emotions like leftward slant writers.

These people may sometimes appear to be a bit of  "Spock" of Star Trek.

(+) management, leadership
(-) fire fighting