As the joke goes, there are two kinds of people: those who divide up the world into two kinds of people, and those who don't.
Well, I have a number of ways to divide up people into either of two buckets. Here's my first pairing:
Those who want to engage people they interact with on a person-to-person human basis, and ... those who don't.
In the first category, I remember a clerk at a lunch spot who just made my day: I was juggling several purchases (sandwich, fruitcup) along with my briefcase, and she suggested I park my purchases at her register while I got my drink. It was such a small thing! She was just so sunny and good-natured. I couldn't help smiling about it, and I made it a point to compliment her to her manager.
Related to this one are people who look for opportunities to do more, to go a little further, to help someone a little bit more, to make something better, and ... those who want to do the job, and only that. They do the least they have to, and that with a minimum of grace.
You know your own reactions to people in the latter categories.