Multiracial boom reflects racial and ethnic complexity

For the 2010 Census, René D. Flores, a Mexican American college professor, marked his race as “white.”

Since then, a genealogy test revealed he has 43% Native American ancestry. He is among millions more people who now identify as having two or more races, or being multiracial.

“I hesitated before because I did not have the cultural upbringing when I was growing up. There are many millions of Americans that are feeling the sameway,” Mr. Flores said.

From McKenzie County, N.D., to St. Johns County, Fla., the growth in the number of people who identified as multiracial on 2020 census responses soared, rising from under 3% to more than 10% of the U.S. populationfrom 2010 and 2020.

The multiracial boom reflects the complex diversity of the U.S. It also may be the result of changes the U.S. Census Bureau made in processingresponses that better capture diversity and how it asked about race and ethnicity to better reflect the nation’schanging mosaic.

In an age of easily accessible DNA testing kits, the growth reflects a deepening of the way Americans think about themselves when it comes to racial identity, experts say.

Juan Manuel Pedroza, an assistant professor of sociology at the University of California, Santa Cruz, said the 2020 results should be regarded with some caution considering the hurdles the Census Bureau faced in getting responses and a history of undercounts in communities of color. Still, the increase in the percentage of people who identified as multiracial is significant and indicative of how the country is changing, he said.

Yes, the country is diversifying. But also, there’s much less stigma attached to being multiracial, and there’s more conversation about it. So someone who marked themselves as strictly white in 2010 may have chosen two or more races this time around in part because of societal changes, Mr. Pedroza said.

Mr. Pedroza pointed to a study from sociologists at Stanford who looked into whether the popularity of ancestry tests can change how Americans respond to survey questions about race and ancestry.

The study examined 100,000 adults in the U.S. who were registered as potential bone marrow donors and who, as a part of their registration, had been asked how much they knew about their ancestry, and how they came to learn it. The Stanford researchers analyzed those responses and found that people who have taken ancestry tests are more likely to identify as multiracial.

Still, that’s highly unlikely to account on its own for the dramatic jump in the numbers.

Mr. Flores, an assistant professor of sociology at The University of Chicago, said younger people might also be more open to identifying as multiracial.

According to 2020 census data the Census Bureau, the number of people who identify as multiracial went from 9 million in 2010 to 33.8 million in 2020, if Hispanics are included. If Hispanics are taken out of the calculation, the multiracial numbers went from 5.9 million to 13.5 million people.

The largest combination of people identifying as multiracial was white and some otherrace, followed by white and American Indian and Alaska Native; white and Black;and white and Asian.

The highest growth rates over the decade for people identifying as multiracial were in states that already had a low multiracial share of the population — Arkansas, Alabama and New Hampshire — which in 2020 was less than 5%.

Since the first census in 1790, the U.S. government has collected data on race and started gathering information on Hispanic ethnic background during the 1970 census. Respondents have only been given the option of putting more than a single race on the census form since 2000, and further changes are likely in the 2030 census.

The Census Bureau says it improved the 2020 race question by adding space for respondents to write in further details about their race, so someone who marked “Black” could also write “African American” or “Jamaican.” When crunching the numbers, Census Bureau statisticians expanded numeric codes in order to better capture a wider range of how people self-identify in the write-in answers.