In 1913, a discovery in South Africa sparked speculation into a possible race of ancient hominids with a brain 25 percent larger than our own, with intelligence to match. However, the Boskop remains also sparked controversy in the palaeoanthropology community, as experts questioned these outlandish claims.
A farmer in the small village of Boskop, 16 kilometers (10 miles) north of Potchefstroom, uncovered the partial remains of a skull identified as belonging to a female of the supposed Boskop race. The skull was reconstructed by taking casts of the fragments, which revealed an apparent cranial capacity of roughly 1,750cm3 (cubic centimeters). In comparison, modern human cranial capacities range from 1,300cm3 to 1,500cm3. In addition to the increased capacity, the skull was longer, narrower, and thicker in places than is typical in modern humans.
More partial remains were found in the surrounding areas of Boskop. A number of partial limb bones and a poorly preserved mandible were also believed to belong to this assumed hominid species – however, the lack of intact remains makes classification difficult, and so the very existence of the Boskop race has been debated and outright denied by experts.
Despite the skepticism toward the characteristics and even existence of the Boskopoids, a 2008 book titled Big Brain: The Origins and Future of Human Intelligence presented some lofty claims as to the intelligence of the species.
Written by Gary Lynch and Richard Granger, two prominent neuroscientists, the book outlines their predictions as to the Boskopoids’ potential capacity for intelligence. Describing an enlarged head with small, childlike features, the book goes on to explain that the Boskopoids’ enlarged brains would lead to a 53 percent increase in the size of the prefrontal cortex, an area of the brain responsible for planning and forward thinking.
Rather romantically, the authors describe the different ways in which modern humans and Boskopoids would recall the experience of walking through a Parisian street. Describing our memory as “the mental visual image of the street vendor, the bistro, and the charming little church,” they then describe the Boskop as being able to recall “the music coming from the bistro, the conversations from other strollers, and the peculiar window over the door of the church.”
In one of the more contested excerpts, the authors describe intelligence in relation to IQ scores, claiming that brain size accounts for 10 to 20 percent of an IQ test score in modern humans. Using this figure they predict that the Boskop, with 30 percent larger brains, would have an average IQ score of 149, while modern humans average between 85 and 115.
While the accuracy of IQ scores to predict intelligence is widely disputed, the specific claims presented in the book have been heavily contested by anthropologists who call into question the authors' backgrounds in relevant fields. One of the experts most outspoken on the matter, John Hawks, published posts regarding the book in his blog, which focuses on palaeoanthropology, genetics, and evolution.
Hawks explains “what happened is that a small set of large crania were taken from a much larger sample of varied crania, and given the name, ‘Boskopoid.’ This selection was initially done almost without any regard for archaeological or cultural associations – any old, large skull was a ‘Boskop’,” emphasizing the difficulty in definitively classifying such scarce and incomplete remains.
Questioning the supposed 53 percent increase in prefrontal cortex size, Hawks speculates this assumption relates to the 10 to 20 percent increase in prefrontal cortex size between humans and chimpanzees. He states there is no reason to assume there would be a bonus expansion of this part of the brain specifically, and that the scale is likely to be relative to overall brain size.
Additionally, Hawks emphasizes the lack of literary evidence for the claims made in the book, with Boskopoids having not been written about by anthropologists since 1958. He goes on to explain “There is no such thing as an ‘IQ estimate’ for a fossil human; that's entirely nonsensical,” questioning why two neuroscientists chose to write about the evolution of the brain using “completely obsolete anthropological information”.
Despite Big Brain: The Origins and Future of Human Intelligence presenting an arguably largely incorrect idea of an extinct super species of Hominid, the remains found in Boskop continue to be a small part of the fascinating story of human evolution in southern Africa.