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Department of Geography


The depopulation of Melanesia: epidemiological versus psychological factors

Melanesia was one of the last regions of the world to be affected by the process of global integration that, arguably, began in 1492 with European colonisation of the New World. This was a process accomplished globally with the help of Guns, Germs and Steel, to quote the title of Jared Diamond’s book. In New Guinea, Solomon islands, Vanuatu and Fiji the resulting depopulation process was commented upon by many observers, for example the New Zealander William Crossan who spent six months on Makira island in 1885-86 bartering tobacco, flour and beads for strings of copra, the new commodity being extracted from the Islands for export to western markets. Crossan’s diary has recently been discovered and throws interesting light on introduced disease and other processes of colonialism. For example, on 23rd September 1885 Crossan wrote “It is doctors they want down here not missionaries, for in the course of a few years, if things go on as they are, there will be no more natives to instruct in the Bible…” (Bayliss-Smith & Bennett 2012: 31).

Population decline was also witnessed by the first generation of social anthropologists. Two examples are William Rivers and Arthur Hocart, who conducted joint fieldwork in the western Solomons in 1908. The influential book edited and partly written by Rivers, Essays on the Depopulation of Melanesia (1922), was mainly based on his own and Hocart’s ethnographic surveys of Simbo Island. Rivers’s field notebooks seem not to have survived, but his genealogies are in the Cambridge University library, and this resource forms one basis for further study.

The project involves an attempt to reconstitute the demographic statistics generated for Simbo by Rivers, using his own primary sources, in order to test his suggestion that rapid population decline was more the result of declining fertility rather than catastrophic mortality from introduced disease (Bayliss-Smith 2005, 2014, 2019). Tim has evaluated and rejected Rivers’s conclusion that childlessness and low fertility stemmed from ‘psychological factors’ connected to the cultural impacts of colonialism. Instead childlessness, and its consequence depopulation, stems from epidemiological impacts, in particular the impact of the sexually-transmitted disease that had been introduced to Solomon Islands. Collaborators include Edvard Hviding (Social Anthropology, University of Bergen, Norway), and Judy Bennett (Department of History, University of Otago, New Zealand).


Relevant publications include:

  • 2019: Population decline in Island Melanesia: Aphrodisian cultural practices, sexually transmitted infections and low fertility. In Simon Szreter, ed. The Hidden Affliction: Sex, Disease and Infertility in History. Rochester, New York: Rochester University Press, pp. 187-218.
  • 2014: Colonialism as shell-shock: W.H.R. Rivers’s explanations for the depopulation of Melanesia. In- The Ethnographic Experiment: Hocart and Rivers in Island Melanesia, 1908. Oxford: Berghahn Books. (See final draft.)
  • 2012: An Otago Storeman in Solomon Islands. The Diary of William Crossan, Copra Trader, 1885-86. Canberra: ANU E Press. (Tim Bayliss-Smith and Judith Bennett, eds.)
  • 2005: Fertility and depopulation: childlessness, abortion and introduced disease in Simbo and Ontong Java, Solomon Islands. Chapter 1 of S. Ulijaszek, ed. Fertility and Reproduction in Melanesia. Oxford and New York: Berghahn, pp. 13-52.
  • 2003: Rainforest composition and histories of human disturbance. Ambio 32: 246-252. (with Edvard Hviding and Tim Whitmore).
  • 2000: Islands of Rainforest: Agroforestry, Logging and Ecotourism in Solomon Islands (with E. Hviding), chapter 6, The great transformations 1880-1910, Aldershot: Ashgate, pp. 1-371.