Jantz's recent research involves measuring the differences in bone size and shape between different Native American tribes. In this research, he challenged work done by Franz Boas, a founder of modern anthropology. The original study, done by Boas in the early 1900s, showed that children born in America had bones closer to other American adults, and children born in Europe had bones closer to those of other Europeans. In 2002, Jantz did his own study to test Boas' findings. He writes that he found no significant difference between the bones of American and European children, but his study receives criticism from many other anthropologists. 