To be precise, this's a way to realize if there's a groundless hatred or prejudice against a particular race in your unconsciousness.
Close your eyes and think of a specific race.
For example, Imagine they're competent professionals like doctors, lawyers, and accountants to help you.
Imagine if they soon become your wife, your husband, your mother-in-law, your father-in-law, your stepbrother, your stepsister, your stepson, and your stepdaughter.
If these two things conflict, the conclusion is as follows: I prefer their ability, but I don't want them to be part of my life!
I'll leave it up to your imagination to see what each person thinks.