The next year in 1960 he moved to University of Amsterdam, where he obtained his MA in political and social sciences in 1967.
He continued his graduate study and obtained his PhD in 1972 under Hans Daudt with the thesis Political integration: the formation of theory and its problems.
[2] After his graduation in 1967 De Vree started his academic career as lecturer at the Europa Institute of the University of Amsterdam.
[2] De Vree was na active member of the Dutch Political Science Association, where he was president from 1975 to 1983.
De Vree is particularly known for the comprehensive formal theory of human behavior, that he had built on throughout his career.