But an increase of 600,000 people from one census to the next was too large to attribute to widespread misunderstandings. Changing racial stigmas and preferences affect the way people identify themselves. In Snipp's grandparents' generation, for example, it was not uncommon for Indian children, many of them educated in boarding schools, to be punished by caretakers or teachers for speaking their own language. Racial laws play a role in how people conceive their identity. Where there were segregated facilities, they could sit in the white section.
Interracial marriage is another substantial factor.
Figures about multiracial ancestry are scarce, but census data indicate that interracial marriages among all Americans rose by more than 800 percent between 1960 and 1990. Large cities bring together a diverse collection of potential partners, thus making intermarriage more likely as the nation becomes less rural. Another analysis of the 1990 census indicates that about 31 percent of native-born Hispanic spouses, ages 25 to 34, are married to others who identify themselves as white. The lowest intermarriage rates are among African Americans, but they are also rising. This issue has prompted organizations of multiracial Americans and their parents to demand that Congress permit multiracial identifications in the year 2000 census.