The number of people who identify as belonging to two or more races keeps climbing with each Census. The number of people identified as both black and white, for example, more than doubled between 2000 and 2010, from about 780,000 to 1.8 million.
Persons identified as "white and black" as a percent of black persons, by age, in 2000 and 2010
A closer look at where this change is happening, and among whom, hints at a substantial shift in how people feel about being multiracial. Brookings demographer William Frey looked at data from the most recent Census and found that Southern states have had the biggest increase among people who ID as both black and white. In his book, The Diversity Explosion, Frey writes that while far fewer people identify this way in the South than the rest of the country, the black-white populations of the Carolinas, Georgia, Mississippi and Alabama tripled between 2000 and 2010, "while Tennessee, Florida, Arkansas, Louisiana and Kentucky were not far behind."
All told, the South accounted for more than 40 percent of all the folks newly identifying as both black and white between the two censuses. "To be sure, the overall numbers of white-black identifying persons are small," Frey wrote at Brookings. "But these shifts — incremental as they may seem — represent a major breakthrough in the blurring of the nation's racial boundaries, once indelibly etched in stone by laws, public and private institutions, and even the census."
What's equally fascinating is how that black-white identification breaks down by age. Frey explains that for every 100 black toddlers under age 5, 15 toddlers are identiﬁed as both white and black. That's another sharp jump since 2000, the first survey where people could pick more than one racial category.
Of course, since these kids are too young to respond to the questionnaire, their parents are identifying them this way. Frey told me that as folks get older, many people whose parents have marked them down as black or white may instead identify as both. "I talked to a few people who have interviewed young people," he said, "and often they're more likely to embrace their multiracial heritage than their parents were."
Even that might not be so cut-and-dried. As we know from history, how folks identify racially has always been a much more complicated calculus than just a question of parentage.