If the prehistoric past reveals different patterns of agricultural development in the societies of the eastern and western highlands, the contemporary configurations of societies in those areas equally sustain the view of a continuum of intensifying agricultural production from east to west. There are certain ‘factors of intensification’ which highlight this continuum. Brown and Podolefsky (1976) have analysed various indicators of ‘agricultural intensity’ in a number of highland societies; Brookfield with Hart (1971) ranked forty-four places in Melanesia on ‘intensity’, concentrating on a wide range of cultivation methods and crop information; and Waddell (1972) has discussed the rise of intensification in the highlands and suggested four ‘core’ areas of greatest intensification. While the meaning of intensification is not always clear, most authors imply the notion of greater inputs (capital, labour, skill, and so on) to land as a measure of intensity. By this rough measure, there is the view that there are areas in the highlands, for example, which are patently more ‘intensive’ than others.

Most discussions of intensification concern the issue of agricultural intensification, population growth and density, and their relationship to a wide range of other features of society (for example, land tenure, group size, political integration, environmental variables, cultivation methods, and so on).