Theories of racial superiority had been around for centuries when, in the late 1800s, eugenics became the science of the age.

Scientists got to work calculating human differences -- skulls, noses, chins and much else. The data became evidence of a racial hierarchy that placed, in one anthropologist's words: "The European or white race at the head of the list, the African or Negro at its foot."

It was the perfect rationale for European imperialism and for Jim Crow laws in the United States.

Franz Boas, a founder of U.S. anthropology, was a reformer much involved in disputing these views of racial superiority. His 1912 study of 13,000 European-born immigrants to the United States and their American-born children concluded that head shape had nothing to do with genetics. Variances, he suggested, could be explained by environmental factors like improved nutrition.

Now, two U.S. researchers -- Cory Sparks and Richard Jantz -- have reanalyzed his data and come to a different conclusion: Effects of the new environment were "insignificant" and differences between parents and children were "negligible in comparison to the differentiation between ethnic groups."

Dr. Boas -- well-intentioned but misguided -- apparently presented only part of his work. Motivated to refute common views of his day, the researchers say, "[he] did have to shade his data some."

Modern science, including the mapping of the human genome, points to few genetic differences between races -- although one, according to Dr. Jantz, is cranial morphology.

The nature/nurture debate -- and its implications -- remains extraordinarily controversial. Montreal-born scientist Steven Pinker, now at the Massachusetts Institute of Technology, argues in his new book, The Blank Slate,that concerns about how scientific research will be interpreted through the lens of societal inequality have stunted academic inquiry.

It is difficult to put oneself in Dr. Boas' shoes now, especially with our knowledge of the genocide that arose from theories of racial superiority. But if science is to have real meaning, it must be devoted wholly to truth. Some may misuse this latest revelation for nefarious purposes. But as Dr. Jantz says, "[We] certainly aren't arguing that scientific racism is something you should go back to. But that doesn't mean cranial morphology is meaningless, either."

Inquiry for inquiry's sake.