He came to Grinnell College in Spring 1919, succeeding Kuang Chao Lee to receive a full scholarship from Grinnell College when Lee graduated. He also took over from Fan Yi Kung as Chinese secretary of the Nankai Club when Kung graduated in 1920. By all accounts Kao was an active student despite his relatively short stay on campus. He played forward on the basketball quintet organized by Lee in Spring 1919 (SB 02/26/1919), and went to the YMCA conference in Lake Geneva, Wisconsin in June 1919 (SB 06/11/1919), for instance. 

Kao graduated from Grinnell in 1920, earning a bachelor’s degree in philosophy and education. He went on to the University of Chicago where he earned a master’s degree in 1922. Next he studied education at Columbia University for only a few months before leaving the U.S. to investigate education in Britain, Germany and France before returning to China in late 1922. Beginning in 1923 he worked as Professor of Philosophy, Professor of Education, and Chair of the Department of Education at Peking University (PKU). He also promoted mass education, his lifelong passion, and in 1925 founded the Yiwen 藝文School in Beijing, where he experimented with the Dalton Plan, an individual-focused pedagogy invented in 1920 by the American educator Helen Parkhurst who emphasized the combination of individual freedom and cooperation among students.   

In 1926 Kao joined the Nationalist party, introduced by Li Dazhao 李大釗, a Peking University colleague and an underground Chinese Communist. In 1927 Kao served as Chair of the Beijing Nationalist Left Alliance 北京國民黨左派大聯盟. He refused to flee Beijing after Li’s execution by the warlord government and was soon arrested himself on a charge of “Communist tendency” in Beijing. Not yet thirty-five, Kao was executed in January 1928. From the prison cell, he wrote the last letter to his wife, mourning that he had run out of time to use his knowledge to benefit Chinese society, even though he had studied education for decades in China and abroad (PKU).