Final answer:
John Dewey did not obtain his doctorate under the supervision of William James, while Mary Whiton Calkins, despite not being formally awarded a PhD, Margaret Floy Washburn, and G. Stanley Hall, did have a more direct connection with James. the correct option is c) John Dewey .
Step-by-step explanation:
psychologists who obtained doctorates while studying under the supervision of William James:
The psychologist who did not obtain their doctorate under the supervision of William James is c) John Dewey. Among those listed, Mary Whiton Calkins, though never formally awarded her PhD due to gender discrimination, completed her studies under James. Margaret Floy Washburn was the first woman to receive a PhD in psychology and was supervised by James. G. Stanley Hall, while an important figure in the history of psychology, did not study under James as he completed his work independently.
John Dewey, often associated with pragmatism and educational reform, earned his doctoral degree from Johns Hopkins University, not directly under James's supervision. It's a common misconception given Dewey's overlapping interests with James and his impact on the field of psychology and philosophy.