When you have a harder time recognizing or distinguishing between members of racial ethnic groups other than your own, what's at work is known as the "cross-race effect."
One cross-race effect theory on racial mix-ups is what's called the "experience-based" hypothesis: We find it easier to recognize and distinguish and remember faces of our "racial in-group" than we do "racial out-groups" simply because we see the in-group features more.
Then there's the related "coding" or "categorization" hypothesis: When we see a member of another race, our minds pay more attention to what makes the person an out-group member than to his or her individual features. We lose some of the distinguishing details in the process.
All you niggas look the same
This is a public poll: others will see what you voted for.
All you niggas look the same 25 votes
All Eurpoeans look alike
All Africans look alike