There is little agreement about the timing and causation of African demographic change after 1900 due to the paucity or poor quality of the statistical resources for much of the modern period. Before 1900, the data are infinitely worse but the debates are no less heated. Yet this lack of consensus is relatively new. Until the 1960s, there was general agreement that the continent's precolonial population had been low and largely stable, limited by violence, slaving, social and economic obstacles to rapid growth such as prolonged breastfeeding and the absence of secure land tenure, and exceptionally high disease loads.
— The Oxford Handbook of Modern African History
by John Parker, Richard Reid