However, the latest Census figures released last month show the growth of interracial marriages is.
According to the new Pew analysis, the overall increase can be attributed to two main factors: the taboo of interracial marriage has diminished over the years and a sustained flow of recent immigration among Hispanics and Asians.
Those two demographic groups were more likely to marry outside of their race or ethnicity, according to the Pew analysis. Thirty-one percent of Asians and 26 percent of Hispanics had interracial marriages in 2008. By comparison, the figure was 9 percent for whites and 16 percent for blacks.
Gender patterns in interracial married fluctuated depending on race. Two out of five Asian women married outside their race in 2008, compared with just one in five Asian men. By contrast, black men (22 percent) were more than twice as likely to marry outside their race as black women (9 percent) among 2008 newlyweds.
Pew researchers pointed to President Barack Obama's black father and white mother to illustrate the overall increase in interracial marriage in the United States.
When Mr. Obama's parents were married in 1961, less than one in 1,000 new marriages was between a black person and a white person. By 1980, the figure was one in 150 new marriages. By 2008, the year Mr. Obama was elected to the White House, it had risen to one in 60.
Due to increasing interracial marriages, multiracial Americans are a small but fast-growing demographic group, making up about 5 percent of the minority population. Together with blacks, Hispanics and Asians, the Census Bureau estimates they collectively will represent a majority of the U.S. population by mid-century.