karin heiberg was born into a norwegian middle-class family in paterson, new jersey (usa), and became politically interested as a socialist in her early teens. she met her husband-to-be when they were 18, but after a short romance she moved to canada with her family, where she lived for six years and was briefly married. after her divorce in canada, she returned to norway planning to complete a doctorate in genetics. she notified stoltenberg that she was back, and they decided to get married within 24 hours of reuniting. she broke off her academic career in science but completed studies in political science at the university of oslo. karin and thorvald stoltenberg were married in 1957.