There are a lot of school of thoughts are are involved to what you have witness or experiences.
You start with a curiosity then you put the pieces together.
For starters, it could be location. A hmong women who lives in a hmong infested place are still safe. She will tend to marry her own kind due to what she has in her surroundings. Like for instance, when I see a hmong chick with a hmong guy, I can't break her up just to be with me. I mean I'm only 3 hours away but this guy is hovering around her like fly on poop cuz he's local and so the local guy will win the battle, 9 out of 10 times. The one time that I won is because I was in town. Love is local first folks. If you hang out with a chick X amount of time, you will win her heart somehow.
Now if I see a hmong chick with a white, black, non asian guy, first reaction is to allow me to guess where she's from. Single asian looking female from the suburb, not poor in statue, educated, probably has a good job, filled up with nothing but "OTHERS" for coworkers so once again, her location is filled up with more "OTHERS" than hmong guys so she is gonna date the guy that clings around to her like leeches.
And to top it off, I don't go into this whole psychological analysis on my women, especially if I am dating a hmong chick. Why? Cuz they all got issues.