How did Louis Agassiz's public support for polygenism affect pro-slavery Americans?

Louis Agassiz’s public support for polygenism—the scientifically unfounded notion that different human races were created as separate species—provided a veneer of academic legitimacy to the ideologies of pro-slavery Americans.12

As a renowned naturalist, Agassiz’s stature lent significant weight to these views. By advocating for the independent creation of races and suggesting a hierarchy of intelligence among them, his pronouncements emboldened the resolve of many pro-slavery white Americans, particularly in the South, who sought to justify the institution of slavery during the mid-19th century. These ideas were part of the broader framework of scientific racism, which sought to categorize human populations in ways that reinforced existing social and political inequalities.12

It is essential to affirm that all human beings possess equal dignity and worth; the use of scientific authority to promote racial hierarchy and justify the enslavement of others is a profound ethical failure that has been thoroughly discredited by modern science.12