De Lange, Beltzaser Johannes Carolus2016-02-222016-02-22195019501950http://hdl.handle.net/11660/2354Abstract not availableafDissertation (M.Ed. (Psychology))--University of the Free State, 1950Intelligence levels -- Social aspectsFertility, HumanBirth controlDie verhouding tussen intelligensie en bevolkingsgroei soos weerspieël deur die Bloemfonteinse skoleDissertationUniversity of the Free State