The number of mixed racial marriages in the United States has doubled in thirty years, a study released by the Pew Research Center said.
Fifteen percent of all US marriages were among mixed race couples in 2010, up from 6.7 percent in 1980, Pew said.
The proportion of mixed race couples, regardless of the date of marriage, stood at a record rate of 8.4 percent in 2010, compared with 3.3 percent in 1980.
"While newlyweds who 'married out' between 2008 and 2010 are very similar to those who 'married in,' judging by characteristics such as education, income and age, there are sharper differences among them based on the race, ethnicity and gender partnerships of the couples," a Pew statement said.
In 2010, 28 percent of Asians and 26 percent of Hispanics participated in mixed marriages, while 17 percent of blacks and 9 percent of whites married someone from a different race.
The genders of mixed marriage partners varied widely. In 2010, about 24 percent of black men married women who were not black, compared with 9 percent of black women.
Among Asians, the pattern is reversed -- 36 percent of women marry outside their community, compared with 17 percent of men.
Mixed marriage rates among white and Hispanic men and women were equal.
Couples in Asian-white marriages were the wealthiest, with median earnings of $71,000 per year, the study said. They also had the most college graduates.
"Just as intermarriage has become more common, public attitudes have become more accepting," Pew said.
Forty-three percent of Americans -- especially young people, college graduates and residents of northeastern and western states -- believe growing numbers of mixed marriages are positive for society.
Only 11 percent of Americans believe mixed marriages are negative, and 44 percent think they make no difference.
The Pew study however showed the divorce rate is higher for mixed marriages, with variances for the races and gender of the partners.
Mixed race marriages were illegal in most states until the mid 20th century.
Fifteen states kept laws against mixed race marriage on the books until 1967, when a US Supreme Court decision -- Loving v. Virginia -- declared the so-called anti-miscegenation laws illegal.