Help with a Persuasive Essay

For thousands of years, people have put one another into multiple categories: different races, nationalities, political allegiances, creeds, economic classes, etc. What is the best way to classify the various people in your life? 

Write a well-organized persuasive essay in which you explain the best system of classification for the people in your life and why it is the best.  Don't write about ONE class of people, but create a SYSTEM encompassing most / all people you regularly encounter.

There is no assigned minimum word length for the essay, but it should be a complete essay (not random thoughts on the topic, and not just a few words stating a position).