For example, Agassiz was an early and vociferous proponent of such biological quackery as polygenism (the idea that races of humans stemmed from distinct and different ancestors and thus were of separate origin) as well as miscegenation, or racial admixture within a society. Agassiz could also be called a prototypical 19th-century “racial philosopher” because of his curious obsession with comparative brain size and cranial capacity, and their relationship to intelligence among races of humans.
Agassiz, always the charismatic showman, compounded the damage to his own reputation by regaling attendees at a Charleston, S.C., conference with his racial sophistry, which unfortunately encouraged and enabled much of America’s pro-slavery faction. His patrons included the notorious Alabama physician Josiah C. Nott, who, as the owner of nine slaves, sought out Agassiz’s counsel to validate his own theories about the subjugation of blacks through slavery. Nott infamously stated that those indentured achieved their greatest perfection, physical and moral (as well as longevity), in a state of slavery. Agassiz and other scientists who espoused polygenism also emboldened colonialists, who believed that the inherent superiority of the white race gave credence to Kipling’s “white man’s burden" – the obligation and duty of whites to rule over other, presumably inferior, races.
Agassiz’s youth in Switzerland had a powerful influence on his own attitudes toward his family, students, and colleagues. His autocratic father was a merchant with both a manipulative personality and a provincial worldview. He sought to control his son’s career path by repeatedly suggesting that studying to become a zoologist (with two doctoral degrees, no less) was a waste of time and money. Agassiz’s mother was also aggressive, perhaps even abusive. The pressure she exerted on Agassiz’s beautiful and artistically talented wife Cécilie (Silli) Braun to subject herself to her husband’s ambitions left Silli feeling helpless and abandoned.