Once again, science is shaking up our comfortable notions of race and ethnicity. First, there was that whole flap over whether one of America’s Founding Fathers had a black mistress (DNA tests suggested he did). Now an article in Wednesday’s New York Times describes an offbeat in-class experiment at Pennsylvania State University. Students in a sociology class agreed to have the insides of their cheeks swabbed in return for a DNA profile that stated — down to the percentage point — how much white, black, Asian, or indigenous American blood flows through their veins. One student, a self-described “proud black man,” was shocked to learn that he is 48 percent white.

It’s interesting to think what would happen if we all took these kinds of DNA tests. How much would it uproot our lives to learn — as many of us probably would — that our bloodlines flow into previously unknown waters?

The fact that we would be surprised by such news is another reminder that race is — as sociologists like to say — “socially constructed.” That is, race has more of a reality in people’s heads than in the makeup of their genes. If you believe yourself to be black and others see you as black, you are black — even if your DNA begs to differ. The racial category of Hispanic or Latino in the United States (the U.S. Census Bureau categorizes it as an “ethnicity”) is another example of social construction. It includes people of widely varying degrees of European, indigenous American, and African ancestry, but somehow has been boiled down to a single, catch-all identity, bound together more by a perception of shared culture than any strict notion of biology. Early 20th-century Mexican writer José Vasconcelos celebrated this mixed identity, heralding the rise of a “cosmic race.”

Just because race is in our heads doesn’t mean it is trivial or that we can just decide tomorrow to forget about it — after all, how people perceive you often dictates the social circles you dwell in, the opportunities you enjoy, and so on. That said, what is constructed can be reconstructed. If there is any hope to ending ethnic hatreds, it may lie in an acknowledgment that round human beings can no longer be fit into square racial categories. It may depend on the emergence on a truly “cosmic” race of individuals no longer tied to the old lies of racial purity.

Victor Tan Chen Victor Tan Chen is In The Fray's editor in chief and the author of Cut Loose: Jobless and Hopeless in an Unfair Economy. Site: victortanchen.com | Facebook | Twitter: @victortanchen