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A 19th century collection of 1300 skulls—symbolized here by white dots—includes some from enslaved people.

Johnalynn Holland

A racist scientist built a collection of human skulls. Should we still study them?

They were buried on a plantation just outside Havana. Likely few, if any, thought of the place as home. Most apparently grew up in West Africa, surrounded by family and friends. The exact paths that led to each of them being ripped from those communities and sold into bondage across the sea cannot be retraced. We don’t know their names and we don’t know their stories because in their new world of enslavement those truths didn’t matter to people with the power to write history. All we can tentatively say: They were 51 of nearly 5 million enslaved Africans brought to Caribbean ports and forced to labor in the islands’ sugar and coffee fields for the profit of Europeans.

Nor do we know how or when the 51 died. Perhaps they succumbed to disease, or were killed through overwork or by a more explicit act of violence.

What we do know about the 51 begins only with a gruesome postscript: In 1840, a Cuban doctor named José Rodriguez Cisneros dug up their bodies, removed their heads, and shipped their skulls to Philadelphia.

He did so at the request of Samuel Morton, a doctor, anatomist, and the first physical anthropologist in the United States, who was building a collection of crania to study racial differences. And thus the skulls of the 51 were turned into objects to be measured and weighed, filled with lead shot, and measured again.

Morton, who was white, used the skulls of the 51—as he did all of those in his collection—to define the racial categories and hierarchies still etched into our world today. After his death in 1851, his collection continued to be studied, added to, and displayed.

In the 1980s, the skulls, now at the University of Pennsylvania Museum of Archaeology and Anthropology, began to be studied again, this time by anthropologists with ideas very different from Morton’s. They knew that society, not biology, defines race. They treated the skulls as representatives of one diverse but united human family, beautiful and fascinating in their variation. They also used the history of the Morton collection to expose the evils of racism and slavery, sometimes using skulls in lectures and exhibits on those topics.

Then, in summer 2020, the history of racial injustice in the United States—built partly on the foundation of science like Morton’s—boiled over into protests. The racial awakening extended to the Morton collection: Academics and community activists argued that the collection and its use perpetuate injustice because no one in the collection had wanted to be there, and because scientists, not descendants, control the skulls’ fate.

“You don’t have consent,” says Abdul-Aliy Muhammad, a Black community organizer and writer from Philadelphia. “Black folks deserve to possess and hold the remains of our ancestors. We should be the stewards of those remains.” Muhammad and others demanded that the Morton collection, now numbering more than 1300 skulls, be abolished.

In July 2020, the Penn Museum put the entire collection in storage and officially halted research.

“One of the things we are having to grapple with now is the idea of possession,” says Robin Nelson, a Black biological anthropologist at Santa Clara University. When you study biological material from another person, she says, “your research sample is not, in fact, yours.”

That way of thinking could affect many collections in the United States. For example, the Smithsonian Institution’s National Museum of Natural History (NMNH) holds the remains of more than 30,000 people, many Indigenous and some likely enslaved. Many remains were taken from their graves without permission, by scientists following in Morton’s footsteps through the early 20th century. Other remains were from people who died in institutions, who had no say over the fate of their bodies.

Samuel Morton jump-started physical anthropology in the 19th century with his studies of human skulls, but his research was grounded in racist ideas.

Hulton Archive/Stringer/Getty Images

The reckoning over Morton’s skulls is also a reckoning for biological anthropology. “The Morton collection has been a barometer for the discipline from the moment of its conception,” says Pamela Geller, a white bioarchaeologist at the University of Miami who is working on a book about the collection. Open racism drove its founding, and a new awakening to that legacy is now reshaping its future. “It’s always been a gauge for where we are as anthropologists.”

When the skulls of the 51 were sent to Morton, he was already the world’s leading skull collector. Active in the esteemed Academy of Natural Sciences of Philadelphia, Morton had an extensive network of scientifically minded contacts who responded enthusiastically to his requests to send skulls from every corner of the world. Rodriguez Cisneros wrote that he “procure[d] 50 pure rare African skulls” for Morton’s collection. The doctor claimed the Africans had recently been brought to Cuba, but some skulls may have belonged to enslaved Africans born on the island, or to Indigenous Taíno people, who were also enslaved in Cuba at the time. (Whether Rodriguez Cisneros sent 53 skulls or 51 is also somewhat unclear.)

As documented in The Skull Collectors: Race, Science, and America’s Unburied Dead, by Rutgers University historian Ann Fabian, other scientists who sent skulls to Morton included ornithologist John James Audubon, who nabbed five skulls lying unburied on a battlefield during Texas’s war with Mexico; John Lloyd Stephens, whose bestselling accounts of expeditions in southern Mexico and Central America jump-started Maya archaeology; and José María Vargas, an anatomist who was briefly president of Venezuela. Military doctors plucked other skulls from the corpses of Native Americans killed in battles against U.S. forces sent to remove them from their own land.

Still other skulls came from the potter’s fields of almshouses and public hospitals, where U.S. and European doctors had long sourced bodies for dissection. An 1845 petition to the Philadelphia almshouse board noted that patients, fearing their bodies would be dug up for science, often begged to be buried anywhere but the potter’s field “as the last and greatest favor.” The Morton collection contains more than 30 skulls from that potter’s field—14 from Black people, according to a recent Penn report. “If you were a marginalized or disenfranchised human being, then there’s a chance you would end up in Morton’s collection,” Geller says.

Morton sought a diverse collection of skulls because his life’s work was to measure and compare the cranial features of what he considered the human races. Like many scientists of his time, Morton delineated five races: Caucasian, Mongolian, American, Malay, and Ethiopian. Their geographic origins are jumbled to modern eyes, showing how social categories determine race. For example, “Caucasians” lived from Europe to India; the Indigenous people of northern Canada and Greenland were considered “Mongolian,” like the people in East Asia; and the “Ethiopian” race included people from sub-Saharan Africa and Australia.

Morton thought skulls could reveal telltale differences among those races. When a skull arrived, he carefully inked a catalog number on its forehead and affixed a label identifying its race; many of the 51 still bear the words “Negro, born in Africa.”

Morton meticulously measured each skull’s every dimension. He filled them with white peppercorns and, later, lead shot to measure their volumes, a proxy for brain size. The race with the largest brains, he and many scientists thought, would also have the highest intelligence.

Morton found a wide range of cranial volumes within each of his racial categories. But he wrested a hierarchy out of averages: By his accounting, skulls of Caucasians had the largest average volume and skulls of Ethiopians, the smallest. Morton used his findings to argue that each race was a separate species of human.

Bettman/Getty Images

It is strange that there should arise a phalanx of learned men—speaking in the name of science—to forbid the magnificent reunion of mankind in one brotherhood.

Frederick Douglass

Even in the 19th century, not everybody agreed. Charles Darwin, whose theory of evolution wasn’t published until 8 years after Morton’s death, found Morton’s understanding of species facile and his arguments unreliable. Frederick Douglass, in a speech 3 years after Morton’s death, called research that ranked the humanity of races “scientific moonshine.” “It is strange that there should arise a phalanx of learned men— speaking in the name of science—to forbid the magnificent reunion of mankind in one brotherhood. A mortifying proof is here given, that the moral growth of a nation, or an age, does not always keep pace with the increase of knowledge,” he said.

Despite those critiques, Morton’s approach helped lay the foundation for the burgeoning field of physical anthropology. U.S. and European museums vied to build “massive bone collections,” exploiting colonial violence to gather bodies from all over the world, says Samuel Redman, a white historian at the University of Massachusetts (UMass), Amherst, and author of Bone Rooms: From Scientific Racism to Human Prehistory in Museums. In the early 1900s, Aleš Hrdlička of NMNH, who helped found the American Association of Physical Anthropologists in 1928, continued to use human remains, often stolen from Indigenous communities, to study race and promote eugenics. Hrdlička, who was white and whom Redman describes as “deeply racist,” was the driving force behind NMNH’s skeletal collection. Last month, the association he founded changed its name to the American Association of Biological Anthropologists to separate itself from the discipline’s overtly racist past.

“All of us who stand in this field have inherited this history,” says Rick Smith, a white biocultural anthropologist at George Mason University. “It’s on us to figure out what to do about it.”

In 1982, when Janet Monge, a white biological anthropologist at the Penn Museum, took charge of the Morton collection, she recognized its potential as a tool to explore anthropology’s racist past. She also saw it as a valuable repository of the myriad physical differences among humans, in traits unrelated to the social constructs of race.

For example, in the late 1990s, a paper claimed that certain skull traits in the nasal cavity were unique to Neanderthals. But the researchers had only used modern human skulls from Europeans for comparison. A University of Pennsylvania student, Melissa Murphy, studied hundreds of skulls in the Morton collection and found some of the “Neanderthal” traits in non-Europeans. “Working with the Morton collection gave me a background in understanding human variation I never would have had otherwise,” says Murphy, who is white and now a biological anthropologist at the University of Wyoming.

Between 2004 and 2011, Monge and colleagues expanded scientific access to the Morton collection by using computerized tomography (CT) to scan the skulls and thousands of others held in the Penn Museum. The scans, available online, “really democratized the research process,” says Sheela Athreya, a biological anthropologist at Texas A&M University, College Station, who is Indian American and studied with Monge. Monge says more than 70 scientific papers have been published using the Morton scans, on such topics as how tooth alignment has changed over time and how skull growth during childhood affects adult cranial shape. The Penn Museum’s website lists more than 100 researchers who used the Morton collection from 2008 to 2018.

Meanwhile, the remains of Native Americans in collections became an ethical and legal flashpoint. In 1990, Congress passed the Native American Graves Protection and Repatriation Act (NAGPRA), requiring federally funded institutions to inventory Native American remains in their collections and to work with tribes to return them to their descendants.

Monge, her students, and colleagues began to dig through historical documents, boosting their efforts to understand where the skulls in the Morton collection came from and contacting tribes about bringing some back home. More than 120 of the 450 or so Native American skulls from the collection have been repatriated.

All of us in this field have inherited this history. It’s on us to figure out what to do about it.

Rick Smith, George Mason University

In researching the skulls’ origins, Monge says, “You come to appreciate the people of the collection.” Other scholars explored the identities of remains not subject to NAGPRA, often under Monge’s guidance. In 2007, one student completed a dissertation on the 51, combining historical analysis with a study of the skulls themselves. Some skulls had filed teeth, then a rite of passage in some West African communities, supporting the idea that the people had grown up in Africa.

The 51 and other skulls were eventually moved to glass-fronted cabinets lining an anthropology classroom at the Penn Museum. There they hovered, year after year, around students learning to study human bones. Monge also used skulls from the collection in classes, public talks, and museum exhibits on how anthropology had helped codify the idea of race and the resulting inhumanity. For example, at the African American Museum in Philadelphia, Monge showed vertebrae fused to the skull of one of the 51, a “major trauma” caused by a painful collar the person was forced to wear. “When you can see what slavery did to the body, it’s overwhelmingly powerful,” says Monge, who recalls audience members crying.

Such honest, public acknowledgment of the collection’s violent past was rare among museums, Athreya says. But in 2020, a renewed reckoning with racism prompted yet another re-evaluation of the collection.

In 2017, on his second day in an archaeology class held at the Penn Museum, Francisco Diaz looked to his right and found himself staring at a skull with the label “Maya from Yucatan” pasted to its forehead. Diaz, an anthropology doctoral student at Penn, is Yucatec Maya, born on Mexico’s Yucatán Peninsula. In class, skulls from Black and Indigenous people were “just made part of classroom décor,” he recalls. “You have this institution that has done this type of work on Indigenous people, and then one of you shows up,” he says. Seeing that skull in his classroom, “It’s kind of like saying, do you really belong here?” This year, he wrote an essay on how study and display of the skulls dehumanized the people they belonged to.

The 51 themselves drew renewed attention in 2019, after a presentation by a group of Penn professors and students investigating the university’s connections to slavery and scientific racism. “I was shocked by what I heard,” says Muhammad, who attended the presentation. Muhammad wrote op-eds and started a petition to return the 51 and skulls from two other enslaved people to a Black community—either their descendants or a Black spiritual community in Philadelphia. “These people did not ask to be prodded, they did not ask to be dissected, they did not ask for numbers and letters to be imprinted upon their remains. They were brutalized and exploited. They had their lives stolen from them. And they deserve rest,” Muhammad says.

After the murder of George Floyd in May 2020 sparked protests for racial justice around the country, more and more people within and outside Penn began to see the Morton collection as a present-day perpetuation of racism and its harms, rather than just a historic example. Until last summer, most researchers thought “the science is justified because we’re doing it thoughtfully. And this moment brought to bear, no, that’s not enough,” says Rachel Watkins, a Black biological anthropologist at American University.

Even with recent research that strove to be respectful, it was almost always scientists who decided how and why to study the skulls, not their descendant communities, Athreya notes. “We were speaking for people without them at the table,” she says. To move forward ethically, “Those of us in power are going to have to give up some.”

Among anthropologists, Nelson says, “There’s a mixture of guilt and fear. Guilt for the ways we have engaged with these kinds of materials and benefited from the data collected in ways that we now may find reprehensible. But there’s also fear because we don’t know what the field is going to look like [without those practices].”

Yet examples of inclusive, respectful biological anthropology exist. For example, back in 1991, when construction in New York City uncovered the earliest and largest known African burial ground in the United States, Black New Yorkers who identified themselves as a descendant community guided research, and the more than 400 excavated individuals were reburied in 2003. That project has served as a model for others, including for the remains of 36 enslaved people recently found in Charleston, South Carolina (see sidebar, below). But for remains collected a century or two ago, like the Morton collection, applying the same principles can be challenging.

In July 2020, the Penn Museum moved the skulls in the classroom, including the 51, to join the rest of the collection in storage while a committee discussed what to do with it. Protests continued. “Black Ancestors Matter,” proclaimed one sign at an 8 April protest.

Four days later, the Penn Museum apologized for “the unethical possession of remains” and announced an expanded repatriation plan for the Morton collection. The museum plans to hire an anthropologist of color to direct repatriation, actively identifying and contacting as many descendant communities as possible and welcoming repatriation requests from them, says Penn Museum Director Christopher Woods, who is Black. The museum has also suspended study of the CT scans while it develops a policy, to be enacted this fall, on the research and display of human remains.

These people did not ask to be prodded, they did not ask to be dissected. … You don’t have consent.

Abdul-Aliy Muhammad, Philadelphia community organizer

Repatriation can be the first step toward building the relationships that make future community-led research possible, says Dorothy Lippert, an archaeologist and tribal liaison at NMNH and a citizen of the Choctaw Nation. “People think about repatriation as something that’s going to empty out museum shelves, but in reality, it fills the museum back up with these relationships and connections,” she says.

Monge, too, welcomes the new focus on repatriation. “I see a lot of great—honestly, better!—potential research with the collection,” she says. “The science person in me says that science can help us a lot” with identifying descendant communities and answering questions they may have about their ancestors. For the 51, Monge thinks analyzing their DNA could answer long-standing questions about their ancestry and descendant communities, which may include both Black and Indigenous people. Once identified, those communities should have decision-making power over the 51, she says.

But some people don’t want scientists unilaterally deciding to do more research on the 51. “Healing can’t happen at the site of harm,” Muhammad says, quoting Black artist Charlyn/Magdaline Griffith/Oro. Muhammad’s trust in scientists further eroded beginning 21 April, when news emerged that anthropologists at Princeton University and Penn, including Monge, had kept a sensitive set of remains and used them in teaching: bones presumed to be the remains of Tree and Delisha Africa, who were killed in 1985 when the city of Philadelphia bombed the MOVE community, a Black activist group. (Monge declined to comment because Penn is investigating.)

Muhammad thinks repatriating the skulls of enslaved Black people in the Morton collection to a Black spiritual community in Philadelphia would be more meaningful than launching research to trace their genetic ancestry. “Black people have experienced generational displacement, so there are descendants of these people potentially everywhere and nowhere,” Muhammad says. “Ultimately I want them to be in the hands of Black people who love Black people.”

Each repatriation case will be unique, says Sabrina Sholts, a white curator of biological anthropology at NMNH. But she and others will be watching Penn’s process. “There are many ways [repatriation of the Morton collection] could go that will be really important for all peer institutions and stakeholders to see,” she says.

NMNH, like other museums, including the American Museum of Natural History in New York City, is only now beginning to assess how many remains of enslaved African Americans may be in its collection. “What’s stunning to me is that we don’t even know” how many are held, says Sonya Atalay, a UMass archaeologist who is Anishinaabe-Ojibwe. Ultimately, she and others hope the United States will pass a repatriation law that applies to African American ancestral remains. Many biological anthropologists say institutions should also establish review processes for work with ancestral remains, similar to how institutional review boards evaluate the ethics of research with living people.

On 10 June, the Penn Museum announced it had formed a community advisory group, including Muhammad and other members of Philadelphia community organizations and spiritual leaders, to review the case of the 14 Black people from the Philadelphia potter’s field and consider how to respectfully rebury them. Woods says he hopes a decision about their future will be made by year’s end. That process could inform future work to repatriate the 51. For now, they are still waiting.