It has been suggested that the idea of complementarity came from outside physics, some arguing that the roots of the idea came from the discussions with his father, Christiansen and the philosopher Hoffding when he was still at school.
Ito ay iminungkahi na ang mga ideya ng complementarity nagmula sa labas ng physics, ilang arguing na The Roots ng mga ideya ang dumating mula sa mga talakayan sa kanyang ama, Christiansen at ang talisik Hoffding kapag siya ay pa rin sa paaralan.