When the rate of increase of European populations accelerated in the second half of the eighteenth century, European economists elaborated a theory of interrelationships between environment, population, and technology, which continues to be applied by many social scientists who are dealing with problems of development of primitive societies. The basic characteristic of this theory is that it deals with demographic trends as an adaptive factor: It assumes that a given environment has a certain carrying capacity for human populations, defined as the number of persons who can be accommodated in that region under the prevailing system of subsistence. Population is kept within the limit for subsistence in a particular environment by customary restraint on the number of births or by high rates of mortality, including various forms of infanticide. According to this theory, over the long run primitive societies tend to have a rate of zero population growth. The rate rises above zero if improvements in the technology of food production increase the carrying capacity of the environment, but only until the new limit is reached, after which the rate of population growth again returns to zero.

This reasoning suffers from two main weaknesses: First, the theory focuses exclusively on the technology of food production, ignoring the effects of technological changes in other areas and the effects of the environment; secondly, the theory ignores the effects of demographic change on both environment and technology.