Joseph Frijda was the son of Lion Joseph Frijda and Jetta Sander. He was first married in Den Haag 8 December 1903 to Alida Swaep. The couple had two children. 18 November1931 the couple divorced in Utrecht.
Joseph Frijda married Rosa Jacoba de Leeuw in Utrecht on 19 December, 1940. At that time he was member of the board of the NIK.
The two children of Joseph Frijda's first marriage survived the war.
Amsterdam Municipal Archives; record card of Joseph Frijda
Biography