[3] In 1928, he held an important lecture on "The Natchez Social System' in New York City and in Leiden, his students founded the Ethnological Debating Society W.D.O.

[4][5] In 1952, he gave a commentary on Claude Lévi-Strauss's theory of kinship and highlighted the significance of double descent or bilinealism in explaining some of the features of affinal arrangements which Dutch ethnologists had previously researched in Indonesian related subjects.

The Leiden tradition was set by J. P. B. in his second inaugural lecture (1935) with the concept of Ethnological Field of Study; its focus being the structural core of Indonesian societies.

According to him, four elements constitute this structural core: circulating connubium, double unilineality, dual symbolic classification, and resilience from foreign cultural influences.

[9] In 1949, he started a seminar on the subject of "the structural analysis systems of kinship and marriage", under urging by his nephew Patrick who found the book "Les structures élémentaires de la parenté" by Claude Lévi-Strauss (1949).

[11] One of these was the doctoral thesis of his nephew, Patrick Edward de Josselin de Jong, on the subject of Minangkabau and Negi Sembilan: Socio-Political Structure in Indonesia which was defended by the author on December 19, 1951.

Another was the thesis of Jan Pouwer, Some aspects of Mimika Culture, Netherlands South-West New Guinea (1955, in Dutch), based on fieldwork in Southwest Papua, which led to a career as professor at the universities of Amsterdam, Wellington, and Nijmegen.