ONE PAIR OF researchers who surfaced those connections, Howard University evolutionary biologist Stacy Farina and her husband, Matthew Gibbons, began reading sections of "Sociobiology" while stuck at home during the Covid-19 pandemic. They were taken aback by what they found.

"I had read some chapters of 'Sociobiology' as a grad student," said Farina. "And there's a lot of really great science in there. It's a very interesting book. And I had no idea that the last chapter had any of that stuff in it." Part of her motivation for digging into Wilson's work, she continued, was a sense of gaps in her own training. "I am frustrated with the lack of education about these issues in evolutionary biology."

Later, during a Library of Congress workshop for Howard faculty, Farina asked if the Library had archival material on Wilson. Sure enough, the institution holds his personal papers -- including boxes of documents related to the sociobiology wars. When she and Gibbons perused the collection, they were drawn to four folders labeled with the name of J. Philippe Rushton, a Canadian psychologist who, starting in the 1980s, published studies arguing that substantial genetic differences existed between racial groups.

"Population differences exist in personality and sexual behavior such that, in terms of restraint, Orientals > whites > blacks," begins one 1987 Rushton paper published in the Journal of Research in Personality. His work would eventually be dogged by accusations of statistical flaws and ethics violations, and key papers were retracted.

In 2002, Rushton took the helm of the Pioneer Fund, an organization founded in the 1930s to promote eugenics, the idea that humanity can be improved by manipulating which people reproduce. He led the nonprofit until his death in 2012.

On weekends, Farina and Gibbons began returning to the Library of Congress. It was a "nice little escape during the pandemic," said Gibbons, who works as a business development specialist for a public health organization. "Head out in the morning, go to an early session, grab some lunch, and sort of freak out over what the morning session revealed, race the clock and try to document as much as we could before they kicked us out at the end."

The letters, Farina said, demonstrate a warm relationship between Wilson and the psychologist. In the correspondence, which dates from the 1980s and '90s, Wilson expressed support for Rushton's work, and lamented a stifling culture that, he suggested, had prevented him from speaking more freely, referring in one note to a "leftward revival of McCarthyism." When Rushton's university seemed poised to sanction him for academic misconduct, Wilson sent letters in his defense. He also sent letters to drum up support for Rushton from colleagues at Harvard and at the conservative National Association of Scholars.

Unbeknownst to Farina and Gibbons, a pair of historians were also exploring the Wilson archive. In 2018, University of Illinois historian of science David Sepkoski began working with Wilson's papers while researching a book on biodiversity. Like Farina and Gibbons, he noticed and gravitated toward the Rushton folders.

Struck by what he was reading, Sepkoski began dropping scanned images of letters into a Dropbox folder he shares with Mark Borrello, a historian of biology at the University of Minnesota. "I'm sure I called you from the archives, and was like, 'You're not gonna believe this,'" Sepkoski told Borrello during a recent Zoom conversation with Undark. The two began sketching out a book project on Wilson.

The correspondence, Sepkoski and Borrello now say, suggests that Wilson was carefully managing his public persona -- even as he quietly continued his dispute with his left-wing critics. 

Providing comments on one Rushton paper -- which applied a famous Wilson theory, meant to examine reproductive differences between different species, to argue that Black and non-Black people pursue different reproductive strategies -- Wilson was effusive. "This is a brilliant paper," he wrote, "one of the most original and heuristic written on human biology in recent years."

"Whether it can even be published in this or some other journal devoted to human sociobiology," Wilson wrote later in his comments, "will be a test of our courage and fidelity to objectivity in science."