Tilghman offers scientific views on 'vexing' issue of race

Princeton University President Shirley M. Tilghman broached the charged subject of race Tuesday, March 9, employing her powers of analysis as one of the world's leading molecular biologists to inquire whether the modern science of genetics has provided any answers yet to what she called "one of the most vexing issues facing this country, and indeed the rest of the world."

She also traced science's past failures to grapple fairly with racial classifications, noting that it is also the responsibility of the public as well as scholars in the humanities and social sciences to keep scientists from making the same mistakes now.

In an hourlong address titled "The Meaning of Race in the Post-Genome Era," Tilghman touched on some long-discredited theories of racial classification such as phrenology and described the more nuanced findings of current genetic inquiry which, she said, reflect a "tension between similarity and difference." Though there are small, and sometimes significant, differences among all humans, the genetic material or genomes of any two people are 99.9 percent identical, she said. Current evidence shows that the genetic differences between individuals are significantly greater than differences between groups.

And no one, she said, yet knows what those differences really mean.

"While it is clear that individuals whose ancestors hail from different parts of the planet can be genetically distinguished from one another with high confidence, we know almost nothing about how those differences translate into differences in biologically important characteristics," Tilghman said. "The reason is simple -- most of the complex human characteristics we might wish to understand, like susceptibility to common diseases such as heart disease or stroke, or traits such as athleticism, aggressiveness and especially intelligence, are the consequences of the action of many genes acting in concert, not single ones, and the tools we need for identifying and studying those genes are proving to be very elusive."

The address, the annual James Baldwin Lecture, was sponsored by Princeton's Center for African American Studies and held in Richardson Auditorium in Alexander Hall. The lecture is designed to celebrate the scholarship of a distinguished Princeton faculty member and provides an occasion for the University community to reflect on the issue of race in American culture.

Eddie Glaude, the William S. Tod Professor of Religion and chair of Princeton's Center for African American Studies, praised Tilghman for her strong, sustained support of the center and for her willingness to speak out about the challenges of race. (Photo: Brian Wilson)

Eddie Glaude, the William S. Tod Professor of Religion and chair of center, praised Tilghman for her strong, sustained support of the center, introducing her as "Sister President," a term first used by Cornel West, the Class of 1943 University Professor in the Center for African American Studies.

"This was a historic event," Glaude said later, at the close of the speech. "President Tilghman delicately balanced the insights of genome research with its dangers. But, perhaps more importantly, she demonstrated her commitment to 'thinking out loud' with others about the challenges of race in these times."

Tilghman used levity at some points, projecting PowerPoint images of humorous political cartoons poking fun at scientific advances. She grew somber, however, as she urged the public to be watchful for bias in continuing scientific projects, listing past studies that were based on prejudice, rather than careful observation. "I am sorry to have to say that too often when science has been brought to bear on the issue, the outcome has not yielded enlightenment," she said.

Tilghman said she and Cornel West (above), the Class of 1943 University Professor in the Center for African American Studies, have agreed about the need to create an environment at Princeton where students can "imagine themselves in someone else's skin." (Photo: Brian Wilson)

The great 18th-century Swedish taxonomist Carl Linnaeus, she noted, offered a classification system for humans that conflated race with character, making sweeping generalizations about the traits of categories of peoples. The system persisted for centuries, she said, protected by the shield of scientific credibility. Phrenology, another field of inquiry founded in the late 18th century, ascribed certain qualities of mind to specific brain regions. The shape, size and unevenness of the skull, phrenologists argued, could reveal how various faculties had developed. Its practitioners were doomed ultimately by their own illogical practices, Tilghman said, starting off with their conclusion -- their perceived sense of the superiority of the European or Caucasian people -- and then seeking data to confirm that false premise.

What Linnaeus, the phrenologists and many others had in common, she said, was deep-seated racial prejudice. It "biased the way in which they framed their questions, designed their studies and analyzed their data," Tilghman said. Society can learn from this, she added. "It would be imprudent for us to think that such biases cannot creep into our thinking about race in the post-genome era," she said.

As a consequence of the slow migration of humans out of Africa thousands of years ago and across the planet, it is possible to differentiate among people from widely dispersed geographic regions. "Only when we compare populations that are geographically separated from one another and with whom little admixture has occurred do differences become sufficient to distinguish one group from another," Tilghman said.

At the same time, however, scientists are finding that genetic distinctions between individuals defined to be of different races, based on physical and cultural characteristics, are declining rapidly, she said. Adding to the complexity, researchers are discovering that people can look very different from others even though their genetic ties can be very closely linked. The Ainu people of northern Japan, for example, possess different hair and skin color from most other Japanese people but are very closely related in their genomes.

Members of the University community gathered in Richardson Auditorium to hear Tilghman describe some of the more nuanced findings of current genetic inquiry. (Photo: Henry Vega)

"It is certain that (there will be) debates within the scientific community about whether the historic descriptors of race or ethnicity are valid any more, or indeed ever were, and whether they should be replaced with more robust information about genetic ancestry," Tilghman said. "My own view is that the attempts to stop the progress of science have been remarkably unsuccessful over time, and the benefits of understanding the impact of human variation outweigh the risks."

Princeton and hubs of intellectual inquiry like the Center for African American Studies, she said, play a vital role in the ongoing debate about the meaning of race in a post-genome era. Quoting the Rev. Martin Luther King's statement that "darkness cannot drive out darkness; only light can do that," she closed by saying, "At Princeton, we are in the business of generating light." 

For the first time, Princeton University's Office of Communications and Broadcast Center operated a live video feed of Tilghman's speech that allowed Facebook and Twitter users to post comments online in real time. Several chatters identified themselves as alumni.

At the close of her lecture, several Princeton students asked questions of Tilghman, prompting remarks on the importance of diversity, the need to create more courses in areas such as African American or Latin American studies to draw in students and the U.S. Census. (Photo: Brian Wilson)

Some who weighed in applauded Glaude and the center for hosting the event. Some offered extemporaneous commentary on Tilghman's words as she worked through the speech. "We are all African," wrote one viewer as Tilghman displayed migration charts of humans over history. Still others waxed philosophical. "Cultural identity is a state of mind, not a state of place," one person wrote. Another said: "If throughout history the scientists have based their studies selectively to tell the story they wanted to tell, how do we have faith in the scientists of today who may be doing the same?"

Of the hundreds attending the event, many said they were struck by Tilghman's earnestness to convey the science accurately and communicate that the topic must be discussed and debated for humanity to advance and avoid the pitfalls of the past.

"I thought the speech was powerful because she seamlessly tied biological science, race and public policy in a way that so fluidly crystallized the humanity at the center of it all," said Karen Jackson-Weaver, associate dean for academic affairs and diversity in the Graduate School. "I especially enjoyed the historical aspect of it and her unpacking of the biological determinism that comes out of history and race and prejudice and bias."

She added that she hopes to see more of this type of forum so that members of the University community can "really engage and debate issues that are still with us in many ways."

Keith Wailoo, a distinguished visiting professor in Princeton's Center for African American Studies, was one of the audience members who questioned Tilghman on a host of issues regarding race, prompting her to note that much of current scientific findings reflect a "tension between similarity and difference." Though there are small, and sometimes significant, differences among all humans, the genetic material or genomes of any two people are 99.9 percent identical, she said. (Photo: Brian Wilson)

Alison Goldblatt, a Princeton sophomore who is majoring in psychology, said that the issue of race greatly complicates the kind of human studies research she ultimately intends to do. One wants to respect a person's sense of identity and heritage, she said, but, at the same time, one doesn't want to engage in stereotyping. "I found the speech really interesting -- it will give me more to think about," Goldblatt said. "I believe it will take a while before we all have clarity on this issue."

Howard Taylor, a professor emeritus of sociology who guided Princeton's Program in African American Studies during its early years, commended Tilghman for the content of her presentation as well as her willingness to tackle the controversial subject. "I thought the speech was extremely valuable," said Taylor, an expert on race and ethnicity. "She brought us up to date on all the current science. I can see what she is saying and how it holds up under varying conditions."

During a question-and-answer session, Tilghman discussed the University's commitment to diversity and maintaining an active dialogue about race. She repeated a conversation she had with some students and Cornel West, stationed in an aisle seat not far from her, in which she said they wanted to create an environment at Princeton in which students could "imagine themselves in someone else's skin."

Howard Taylor, a professor emeritus of sociology who guided Princeton's Program in African American Studies during its early years (at center), commended Tilghman for the content of her presentation as well as her willingness to tackle the controversial subject. "I thought the speech was extremely valuable," Taylor said. (Photo: Brian Wilson)

Asked whether she should mandate that students take courses in areas such as African American or Latin American studies, Tilghman said she prefers "carrots over sticks" and she wants to create a situation where such courses are so compelling that students can't resist signing on. 

When queried about the current U.S. Census, she agreed that the new genetic information underlying modern ideas of race was creating difficulties in how people categorize themselves and fill out forms that ask for racial classifications. The classification for Hispanics, she said, is no longer meaningful in terms of genetic identity. Science is bringing us to a place, Tilghman said, where some terms are no longer useful identifiers, at least from a genomic point of view.

The Baldwin Lecture will be posted for viewing on Webmedia.