Origin: A Genetic History of the Americas

Another major implication of polygenism was outlined by naturalist
Jean Louis Rodolphe Agassiz, a contemporary of Morton’s. Agassiz
postulated that different species were created in different regions of the
world according to which climates were most suitable for them, and thus
did not—could not—move very far from their original homelands. The
same was true, Agassiz argued, of humans: Each race was created
individually and separately on its own continent, and migration was the
exception, not the norm, in human history.
Therefore, understanding the origins of each race could help scientists
understand the history of humanity. Morton himself was particularly
interested in the racial origins of Indians. In his best-known work, a study
of Native American morphology called Crania Americana (1839), Morton
suggested that Native Americans were
marked by a brown complexion, long, black, lank hair and deficient
beard. The eyes are black and deep set, the brow low, the cheekbones
high, the nose large and aquiline, the mouth large and the lips
tumid [swollen] and compressed. The skull is small, wide between
the parietal protuberances, prominent at the vertex, and flat on the
occiput. In their mental character the Americans are averse to
cultivation, and slow in acquiring knowledge; restless, revengeful,
and fond of war, and wholly destitute of maritime adventure (27).
This description is remarkable to 21st-century readers for its bigotry, of
course, but also for its curious combination of physical and nonphysical
traits. Today our folk classifications of races tend to be based mainly on
physical features: skin color, hair color, the shape of the eyes and nose.
Terms like “averse to cultivation” sound very strange to a modern reader
(although if you dive a bit deeper into the racist cesspool you will certainly
still encounter claims about IQ and personalities and so forth).
But to a 19th-century medical man with an anthropological bent, this
blending of physical and nonphysical traits was central in understanding
how humans were divided into races and how those races were ranked
relative to each other. It became the central preoccupation of physical
anthropology in the United States, a new discipline founded by a small