Psychologist who proposed influential theories on learning and human behavior, leading the way for modern educational psychology. He was also the president of the American Psychological Association and a member of the board of the Psychological Corporation.
He was the first psychologist to carry out experimental research on non-human subjects, with his doctoral thesis focusing on animal intelligence.
To help with the army enlistment efforts in WWI he devised two multiple choice tests used to classify recruits; Alpha tests were given to all soldiers who could read, and Beta tests, with pictures, to soldiers who couldn't.
He had five children with wife Elizabeth Moulton.
As with another prominent psychologist, Lewis Terman, his views on human intelligence were often shaped by his belief in eugenics.