The motivation for the early studies of biological anthropology are, by today's standards, quite controversial. Anthropologists in the mid-1800s were seeking to find physical data to support the idea that "civilized races" were smarter and more superior to "uncivilized races." They studied the skulls of Native Americans and other nonwhite peoples, searching for evidence that the brains of white people were bigger and better, hence their social and economic superiority. At the time, many looked to this "evidence" as justification for slavery. As history progressed toward World War II, the notions of physical reasons for superiority of certain races fueled the fire of the Nazi agenda in Germany.
Perhaps in response to the nightmare of World War II, the field was rebuilt intellectually in the 1950s by anthropology scholar Sherwood Washburn. Known for his holistic approach toward examining human evolution, Washburn threw out the notion that skull measurements held any value in researching groups of people. He advocated an interdisciplinary approach to anthropology and felt his colleagues instead should be focusing on the dynamics of how primates developed and diversified from earlier species over time (evolution) and how they changed genetically over generations in response to their environments (adaptation). He argued that the field should be based in human evolution rather than racial classification, and that the scientific investigations should be rooted in studies of how humans fit into the biology and behavior of all primates.
Before Washburn's influence, the field was called "physical anthropology," largely based on the nature of physical measurements of skulls and to differentiate it from "cultural" anthropological studies. But as his ideas started to remold the field into what it is today, the name "biological anthropology" began to take hold. Although it has this unified name, the interdisciplinary subject of study actually acts as more of an umbrella to bring together all sorts of scholars beyond just anthropology, including psychologists, geologists, primatologists, zoologists and many more. Because the field encompasses so many different types of ideas, scholars have broken it down into three parts: primatology, paleoanthropology and human variation (also called human biology).