“The Descent of Man,” 150 years on

In 1871, Charles Darwin tackled “the highest and most interesting problem for the naturalist…the descent of man.” Challenging the status quo, Darwin deployed natural and sexual selection, and his recently adopted “survival of the fittest,” producing scenarios for the emergence of humankind. He explored evolutionary histories, anatomy, mental abilities, cultural capacities, race, and sex differences. Some conclusions were innovative and insightful. His recognition that differences between humans and other animals were of degree, not of kind, was trailblazing. His focus on cooperation, social learning, and cumulative culture remains core to human evolutionary studies. However, some of Darwin's other assertions were dismally, and dangerously, wrong. “Descent” is a text from which to learn, but not to venerate. Darwin saw humans as part of the natural world, animals that evolved (descended) from ancestral primates according to processes and patterns similar for all life. For Darwin, to know the human body and mind, we must know other animals and their (and our) descent with modification across lineages and time. But despite these ideal frames and some innovative inferences, “Descent” is often problematic, prejudiced, and injurious. Darwin thought he was relying on data, objectivity, and scientific thinking in describing human evolutionary outcomes. But for much of the book, he was not. “Descent,” like so many of the scientific tomes of Darwin's day, offers a racist and sexist view of humanity. Darwin portrayed Indigenous peoples of the Americas and Australia as less than Europeans in capacity and behavior. Peoples of the African continent were consistently referred to as cognitively depauperate, less capable, and of a lower rank than other races. These assertions are confounding because in “Descent” Darwin offered refutation of natural selection as the process differentiating races, noting that traits used to characterize them appeared nonfunctional relative to capacity for success. As a scientist this should have given him pause, yet he still, baselessly, asserted evolutionary differences between races. He went beyond simple racial rankings, offering justification of empire and colonialism, and genocide, through “survival of the fittest.” This too is confounding given Darwin's robust stance against slavery. In “Descent,” Darwin identified women as less capable than (White) men, often akin to the “lower races.” He described man as more courageous, energetic, inventive, and intelligent, invoking natural and sexual selection as justification, despite the lack of concrete data and biological assessment. His adamant assertions about the centrality of male agency and the passivity of the female in evolutionary processes, for humans and across the animal world, resonate with both Victorian and contemporary misogyny. In Darwin's own life he learned from an African-descendant South American naturalist, John Edmonstone in Edinburgh, and experienced substantive relations with the Fuegians aboard the HMS Beagle. His daughter Henrietta was a key editor of “Descent.” Darwin was a perceptive scientist whose views on race and sex should have been more influenced by data and his own lived experience. But Darwin's racist and sexist beliefs, echoing the views of scientific colleagues and his society, were powerful mediators of his perception of reality. Today, students are taught Darwin as the “father of evolutionary theory,” a genius scientist. They should also be taught Darwin as an English man with injurious and unfounded prejudices that warped his view of data and experience. Racists, sexists, and white supremacists, some of them academics, use concepts and statements “validated” by their presence in “Descent” as support for erroneous beliefs, and the public accepts much of it uncritically. “The Descent of Man” is one of the most influential books in the history of human evolutionary science. We can acknowledge Darwin for key insights but must push against his unfounded and harmful assertions. Reflecting on “Descent” today one can look to data demonstrating unequivocally that race is not a valid description of human biological variation, that there is no biological coherence to “male” and “female” brains or any simplicity in biological patterns related to gender and sex, and that “survival of the fittest” does not accurately represent the dynamics of evolutionary processes. The scientific community can reject the legacy of bias and harm in the evolutionary sciences by recognizing, and acting on, the need for diverse voices and making inclusive practices central to evolutionary inquiry. In the end, learning from “Descent” illuminates the highest and most interesting problem for human evolutionary studies today: moving toward an evolutionary science of humans instead of “man.”