Marriages between whites and blacks in the United States have become less infrequent, going from being relatively rare 30 years ago to comprising a notable percentage of such unions, a study published Thursday found. A study in the October issue of the Journal of Marriage and Family found that between 1980 and 2008 the rate of intermarriage between the two groups had increased dramatically. Three decades ago just five percent of black men were married to a white woman, a figure than had risen almost threefold, to 14 percent, by 2008. Meanwhile, just one percent of black women had wed white white partners in 1980; a percentage that was up to six percent in 2008. Researchers said the study was completed using data gleaned from the 2010 US Census, and found that black-white intermarriage since 1980 increased by a higher percentage than for any other racial or ethnic group. Despite the dramatic increase, however, black-white intermarriage remains the exception, the researchers said. "The number of marriages between whites and African Americans is undeniably increasing rapidly, but it is still a small number," said Zhenchao Qian, lead author of the study and a professor of sociology at Ohio State University. "Our results point to better race relations in 2008 than 1980, but we still have a way to go. The racial boundary is blurred, but it is still there," said Qian, who conducted the study with co-author Daniel Lichter from Cornell University. "It used to be that race trumped everything, including education, when it came to marriage between blacks and whites; that is changing," the sociologist said. "For the first time, we found that highly educated blacks and whites were more likely to intermarry," Qian said. "That is very significant and is another sign that racial boundaries are blurring."