I remember they thought it was impossible for a one person to be mistaken for Eastern European, Hispanic, mixed-race, Asian, or Polynesian. They believed each person could only look from one background and fit perfectly into categorized boxed looks. They believed it was not possible for someone to look ethnically or racially ambiguous.
I remember they also thought it was not possible for Hispanics, Mediteranean descent or Asians to be multigenerational American meaning from more than 100-200 years ago.