Some scientists may think of themselves as impassive observers and analysts, but even the most talented and rigorous researchers possess biases that can slip into their professional work.

The idea of bias in the scientific enterprise is at the root of a mini symposium, “From Skulls to Scans: How Brain Measurements Have Been Used, Misused, and Misunderstood in the Study of Racial Differences,” being held at the Penn Museum on Thursday, Oct. 4.

Sponsored by the Penn Museum and the Penn Center for Neuroscience and Society, the free event will feature presentations and commentary concerning how the study of brains has been used to highlight differences—both real and invented—between population groups. Janet Monge, a curator at the Penn Museum; Geoffrey Aguirre, an assistant professor in the Department of Neurology in the Perelman School of Medicine; and Dorothy Roberts, a Penn Integrates Knowledge professor, will lead the discussion.

“Even in well-conducted studies, claims regarding brain differences between groups can tell us more about the beliefs of the scientist than they do about how groups of people are different,” says Aguirre.

The mini symposium is an extension of a recently opened exhibition at the museum, “Year of Proof: Making and Unmaking Race,” which explores the debate surrounding a collection of 2,000 human skulls from around the world.

Nineteenth-century physician and scientist Samuel Morton collected and analyzed the skulls to draw conclusions about differences in cranial capacity—a stand-in for brain size—among different populations. Believing that Morton was motivated by racial bias, evolutionary biologist Stephen Jay Gould accused him of scientific inaccuracy in his 1981 book, “The Mismeasure of Man.” But in a study last year, Monge and colleagues re-measured a selection of the skulls in the collection and confirmed that Morton, though perhaps a racist, had been highly accurate in his measurements.

The mini symposium will examine how investigations of the brain, both historic and modern, can shed light on biases regarding race and population divisions. Attendees should be prepared to have their assumptions challenged, says Monge.

“I think the program will bring up questions about things, like what is the relationship of ethnicity to race? What is a population in comparison to race, and what is the meaning of ancestry? We’ll ask why we categorize people this way or that way, and why race, unfortunately—and this is the devastating part of it—has been a tool of oppression of people for hundreds of years,” she says.