"Pure" matrilineal systems are said to be "doomed" because they are incompatible with economic growth. The author argues that descent systems are not always changed by forces beyond control but are manipulated by those who hope to gain. Among the Toak of Zambia the adoption of a patrilineal ideology was never tied to economic development but merely subordinated matrilineal practices to patrilineal aims. The manipulation of both descent systems legitimised the maximation of male control over the unpaid labour of women, children and unmarried men and over scarce land in order to cope with agricultural underdevelopment.