He is married to Cand.polit Randi Marie Haugland, at University of Tromsø.
Graeger got her cand.polit. (equivalent to MPhil) in political science at the University of Oslo in 1994 and defended her doctorate in political science at the same institution in 2007.
He graduated from the University of Oslo with the cand.oecon. degree in 1995, and took the dr.polit. degree in 2001 with the paper Essays on the nature, the scope and the consequences of knowledge.