[2] From 1889 to 1914, he served as the Director of the Naturhistorisches Museum Hamburg, which was destroyed during World War II, and worked on myriapods from 1901 to 1916.

He was a member of the Assembly of University Professors of Hamburg from 1901 and the Faculty Council of Colonial Institute from 1908.

[3] He was one of 7 children of scholar, stage actor and singer Karl Kraepelin (1817–1882), who had also founded a theological college.

Between 1903 and 1904 Karl, accompanied by Emil, set out on a five-month voyage, visiting Ceylon, India, Singapore and Java, and in 1908 they undertook a two-month trip to the United States.

Kraepelin gained worldwide recognition for his commitment to reform science education in schools.