WASHINGTON—Does where we come from tell us whom we are? Why do we come in different colors? Does skin color equal race?

Talking about racial issues can be a never-ending discussion. It’s complicated.

Professor Phil Tajitsu Nash at the Smithsonian's 'Race: Are We So Different?' exhibition on Thursday. (Angie Chung/MNS)

The Census Bureau adopted a question that allowed for checking more than one box to describe ancestry in 2000. Ever since, questions have surfaced about the effectiveness of asking people to affirm their identity.

The notion of race is not a scientific construct, said Phil Tajitsu Nash, an Asian American studies professor at the University of Maryland. But the U.S. needs to have those categories in the Census to create a better understanding of its multiracial population.

During the discussion with visitors at the Smithsonian National Museum of Natural History’s ‘Race: Are We So Different?’ exhibition on Wednesday,  Nash pointed out that people often don’t want to confront the notion of racism, saying they’re opposed to racial society.

“I personally would love to see a post-racial society, but we’re not living in a one now.”

Nash acknowledged that, historically, racial categorization has been used to divide and subjugate certain people — and that there’s no perfect word to describe complicated individuals.

The Census, Nash said, has gotten better at allowing a more granular look into backgrounds, but that it’s still inadequate. “If somebody is seven-eighth European background, one-eighth African background, you can’t check the white box several times.”

The classification of mixed ancestry is an ongoing discussion within the Census community, but there’s a need to classify in some way, Nash said.

“Many people tend to like to associate with people like themselves,” Nash said.

The Census needs to compare the data from previous surveys of the country and pay attention to the characteristics of each group as it evolved, Nash said.

“In 1790, if we were taking a Census, we would look at how many white man we had under 16, how many white man over 16, how many white woman, how many blacks, and how many native Americans,” he said. “And by asking those categories, what have we learned about the world that we’re constructed? White men were allowed to grow up. At 16, a white man could become an adult in the eyes of the law” while others, including white women, were always children or not even on the radar.

The way the Census gathers has information has been changing ever since. The change with the 2000 Census form shows that race still remains a key part of the America’s social and legal make-up. It also tells us that racial divisions are blurring—the very traditional black-and-white division is a story of the past in the multiracial country.

In 2010, 9 million people — or 2.9 percent of the population — chose more than one race. That’s about a 32 percent increase from the 2000 Census, in which 2.3 percent of the population identified themselves as mixed-race.