Johann Friedrich Blumenbach (May 11, 1752 - January 22, 1840) was a German physiologist and anthropologist.
He was born at Gotha, studied medicine at Jena and graduated in 1775 with his MD thesis De generis humani varietate nativa (On the Natural Varieties of Mankind, University of Göttingen), which is considered one of the most influential works in the development of subsequent concepts of human races.
He was appointed extraordinary professor of medicine in Göttingen in 1776 and ordinary professor in 1778. His later works included Institutiones Physiologicae (1787), and Handbuch der vergleichenden Anatomie (1804).
On the basis of his craniometrical research (analysis of human skulls), he divided the human species into five races: the Caucasian or white race, the Mongolian or yellow, the Malayan or brown race, the Negro or black race, and the American or red race. Apart from physical characteristics, he assigned psychological characteristics.
In Blumenbach's day, physical characteristics like skin color, cranial profile, etc., went hand in hand with declarations of group character and aptitude. The "fairness" and relatively high brows of "caucasians" were held to be apt physical expressions of a loftier mentality and a more generous spirit. The epicanthic folds around the eyes of "mongolians" and their slightly sallow outer epidermal layer bespoke their supposedly crafty, literal-minded nature. The dark skin and relatively sloping craniums of "ethiopians" were taken as wholesale proof of a closer genetic proximity to the primates, despite the fact that the skin of chimpanzees and gorillas beneath the hair is whiter than the average "caucasian" skin and that orangutans and some monkey species have foreheads fully as vertical as the typical Englishman or German.
Blumenbach's work included his description of sixty human crania (skulls) published originally in fasciculi as Collectionis suae craniorum diversarum gentium illustratae decades (Göttingen, 1790-1828).
This classification and the scientific concept of human races was widely accepted for about two hundred years, but in the late twentieth century, Homo sapiens sapiens came to be seen as monotypic, i.e. not being divisible into races or subspecies