of economic geography. According to this theory, about 70% of a country's economic development can be predicted by the distance between that country and the equator, and that the further from the equator a country is located, the more developed it tends to be. The theory is the central argument of Philip M. Parker's Physioeconomics: The Basis for Long-Run Economic Growth, in which he argues that since humans originated as tropical mammals, those who relocated to colder climates attempt to restore their physiological homeostasis through wealth-creation. This act includes producing more food, better housing, heating, warm clothes, etc. Conversely, humans that remained in warmer climates are more physiologically comfortable simply due to temperature, and so have less incentive to work to increase their comfort levels. Therefore, according to Parker GDP is a direct product of the natural compensation of humans to their climate. Political geographers have used climatic determinism ideology to attempt to predict and rationalize the history of civilization, as well as to explain existing or perceived social and cultural divides between peoples. Some argue that one of the first attempts geographers made to define the development of human geography across the globe was to relate a country's climate to human development. Using this ideology, many geographers believed they were able "to explain and predict the progress of human societies". This led to warmer climate zones being "seen as producing less civilized, more degenerate peoples, in need of salvation by western colonial powers." Ellsworth Huntington also travelled continental Europe in hopes of better understanding the connection between climate and state success, publishing his findings in The Pulse of Asia, and further elaborating in Civilization and Climate. Like the political geographers, a crucial component of his work was the belief that the climate of North-western Europe was ideal, with areas further north being too cold, and areas further south being too hot, resulting in lazy, laid-back populations. These ideas were powerful connections to colonialism, and may have played a role in the creation of the 'other' and the literature that many used to justify taking advantage of less advanced nations. Huntington also argued that climate can lead to the demise of even advanced civilizations through drought, food insecurity, and damages to economic production. See also Cultural materialism (anthropology) Environmental racism Factor endowment Positivism Social determinism State building Hereditarianism Analysis of Western European colonialism and colonization Colonialism Sociological naturalism States and