Chapter 2 – American Polygeny and Craniometry Before Darwin

Blacks and Indians as Separate, Inferior Species

A Shared Context of Culture

According to Gould, in the 18th and 19th centuries, it was assumed white people were superior to non-white black and Native American people. Gould backs this claim by citing examples of revered American leaders (President Thomas Jefferson, President Abraham Lincoln) who believed in the inferiority of non-white blacks and Native Americans. These shared cultural views, rather than objective data, contributed to both conservative and liberal scientists’ beliefs in racial ranking. 


Preevolutionary Styles of Scientific Racism: Monogenism and Polygenism

Prior to Darwin’s theory of evolution, scientists attempted to prove the various races were different and could be ranked in a hierarchical manner from “greatest” to “least.” Over time, two prevailing theories on this subject emerged: monogenism and polygenism. In monogenism, a system rooted in the Old Testament, God was believed to have created a single race of people beginning with Adam and Even. After the creation of Adam and Eve, the various races “degenerated” in response to climate as they moved away from Eden, with whites degenerating the least and blacks degenerating the most, until eventually, the various races became different species. In contrast to monogenism, in polygenism, the Old Testament was ignored, and the various races were believed to be different species from the beginning. Despite its lack of Biblical support, polygeny became the prevailing theory of racial origin in the United States.


Louis Agassiz – America’s Theorist of Polygeny

Referred to by Europeans as the “American school of anthropology,” polygeny claimed non-white people were born inferior to white people and could never rise above; thus, polygeny was used by many Southerners to justify the treatment of slaves as subhuman property prior to the Civil War.  

The leading figure in polygeny at the time was Swiss immigrant and Harvard University professor Louis Agassiz, who believed the various races were, in fact, separate species. Though he used no hard scientific data to support his claims, Agassiz also believed scientists were “obligated” to rank the races on the basis of differences in mental and physical capabilities.


Samuel George Morton – Empiricist of Polygeny

In contrast to Louis Agassiz, American physician and scientist Samuel George Morton used hard scientific data to support his polygenist beliefs. Between the 1820s and his death in 1851, he collected and measured 1,000 human skulls, theorizing that by measuring the skulls of the various races, he could prove brain size differed between races, and thus, intelligence did as well. Such differences in brain size, according to Morton, would prove the superiority and inferiority of the various races. 

Skeptical of Morton’s conclusions, Gould reanalyzes the data published by Morton and determines Morton not only made fundamental statistical errors in his analyses, but he manipulated the data to support his theory of the superiority of white people when the data, in fact, did not.

After correcting Morton’s statistical errors, Gould concludes Morton’s measurements actually demonstrate no significant difference in skull size between races; rather, Morton’s a priori assumptions about white superiority influenced both his measurements and his analysis, resulting in a false conclusion. 


The American School and Slavery

Though many American polygenists shared the same fundamental beliefs about polygeny as a practice, they differed on whether the separate and unequal status of the various races supported slavery or not. Many Southerners welcomed the polygenist works of Agassiz and Morton as a defense of slavery, but many religious Southerners felt uneasy about doing so, as polygeny lacked a religious foundation. Instead, they defended the practice of slavery by referring to the system of monogeny and its claims of racial degradation following creation.