Interracial marriage in the USA reached an all-time high in 2010, about 15 percent of new marriages — or one in 12 — across the country between spouses of different races or ethnicities.

That's amounts to 4.8 million couples, more than double the number in 1980, according to the Pew Research Center study of census data.

"Interracial marriage has gone from taboo to a rarity, and with each passing year, it's less of a rarity," USA Today quoted Pew's Paul Taylor as saying.

Only about a third of Americans viewed intermarriage as acceptable in 1986, according to center researchers.

The New York Times wrote that distinct patterns emerges when statistics on marriages were broken down by sex and race.

• White-Asian couples have the highest earning power, surpassing white-white couples and Asian-Asian couples in median income.
• Among Hispanics and blacks, those who marry outside their race are more likely to have college degrees.
• Black men marry outside the race at a far higher rate than black women.
• Asian women marry outside the race at a higher rate than do Asian men.

States including Hawaii, Nevada, New Mexico and California, were among the most likely to have couples who "marry out" — more than 1 in 5 — according to the Associated Press. The figure reflected the higher concentrations of Asian and Hispanic immigrants.

Daniel Lichter, a sociology professor at Cornell University told the AP that the results indicated improved race relations in America, while mixed-race marriages and the children they produced were blurring "America's color line."

"The rise in interracial marriage indicates that race relations have improved over the past quarter century," Lichter reportedly said.

"Mixed-race children have blurred America's color line. They often interact with others on either side of the racial divide and frequently serve as brokers between friends and family members of different racial backgrounds."