The Tiwi, a society of former hunter-gatherers of North Australia, are known for their system of polygamy in which females were usually betrothed before birth while males did not marry until their late thirties. Today, the Tiwi are monogamous and youths negotiate sexual relations sometimes in defiance of their parents and elders, sometimes with their assent. Tiwi family patterns show informal continuities with tradition in the motives underlying the sexual choices of young women and the often dramatic conflicts of young men. Drawing on psychoanalysis and family systems theory, the article examines the transmission of family patterns and conflicts across generations in a number of cases. On the one hand, the shift toward monogamy reflects individualization and informalization of social relations. On the other hand, separation and individuation for adolescents is difficult and uncertain, and their conflictual enmeshment in family relations often requires dramatic action.