The share of multiracial babies has risen from 1% in 1970 to 10% in 2013.3 And with interracial marriages also on the rise, demographers expect this rapid growth to continue, if not quicken, in the decades to come.
Yet the Pew Research survey findings suggest that the census’s estimate that 2.1% of the adult population is multiracial may understate the size of the country’s mixed-race population. Taking into account how adults describe their own race as well as the racial backgrounds of their parents and grandparents—which the census count does not do—Pew Research estimates that 6.9% of the U.S. adult population could be considered multiracial. This estimate comprises 1.4% in the survey who chose two or more races for themselves, an additional 2.9% who chose one race for themselves but said that at least one of their parents was a different race or multiracial, and 2.6% who are counted as multiracial because at least one of their grandparents was a different race than them or their parents.4
These findings emerge from a nationally representative survey of 1,555 multiracial Americans ages 18 and older, conducted online from Feb. 6 to April 6, 2015. The sample of multiracial adults was identified after contacting and collecting basic demographic information on more than 21,000 adults nationwide. For comparative purposes, an additional 1,495 adults from the general public were surveyed, including an oversample of non-Hispanic adults who are black and have no other races in their background and who are Asian and no race.