Environmental determinism is a theory that claims that the physical environment, such as landscapes and climate, can significantly influence humans and therefore, the ability to impact society and development. It asserts that physical geographic features such as climate and terrain exert a strong and unmediated influence upon human affairs. The theory states that the physical makeup of an environment can psychologically influence individuals within a population, and this can spread within a population to ultimately define the society’s behavior and culture as a whole.

Environmental determinism has been widely criticized as a tool to legitimize colonialism, racism, and imperialism in Africa, The Americas, and Asia. It enabled geographers to scientifically justify the supremacy of white European races and the naturalness of imperialism. The scholarship bolstered religious justifications and in some cases superseded them during the late 19th century.

Environmental determinism was revived in the late-twentieth century as neo-environmental determinism, a new term coined by the social scientist and critic Andrew Sluyter. Sluyter argues that neo-environmental determinism does not sufficiently break with its classical and imperial precursors. Others have argued that in a certain sense a Darwinian approach to determinism is useful in shedding light on human nature.

Environmental possibilism is an alternative theory that states that even if the environment sets limitations for cultural development, it does not wholly define a culture. Rather, culture is defined by the opportunities and decisions that human beings make in response to dealing with their physical environment.