World-systems theory in the context of "Core countries"

The term Third World arose during the Cold War to define countries that remained non-aligned with either NATO or the Warsaw Pact. The United States, Canada, Japan, South Korea, the Southern Cone, Western European countries and other allies represented the "First World", while the Soviet Union, China, Cuba, North Korea, Vietnam, and their allies represented the "Second World". This terminology provided a way of broadly categorizing the nations of the Earth into three groups based on political divisions. Due to the complex history of evolving meanings and contexts, there is no clear or agreed-upon definition of the Third World. Strictly speaking, "Third World" was a political, rather than economic, grouping.

Since most Third World countries were economically poor and non-industrialized, it became a stereotype to refer to developing countries as "third-world." In political discourse, the term Third World was often associated with being underdeveloped. China was labeled "Third World" for several decades in the 20th century before its robust development of the 21st century. Some countries in the Eastern Bloc, such as Cuba, were often regarded as Third World. The Third World was normally seen to include many countries with colonial pasts in Africa, Latin America, Oceania, and Asia. It was also sometimes taken as synonymous with countries in the Non-Aligned Movement. In the dependency theory of thinkers like Raúl Prebisch, Walter Rodney, Theotônio dos Santos, and others, the Third World has also been connected to the world-systemic economic division as "periphery" countries dominated by the countries comprising the economic "core".

Sociocultural evolution, sociocultural evolutionism or social evolution are theories of sociobiology and cultural evolution that describe how societies and culture change over time. Whereas sociocultural development traces processes that tend to increase the complexity of a society or culture, sociocultural evolution also considers process that can lead to decreases in complexity (degeneration) or that can produce variation or proliferation without any seemingly significant changes in complexity (cladogenesis). Sociocultural evolution is "the process by which structural reorganization is affected through time, eventually producing a form or structure that is qualitatively different from the ancestral form".

Most of the 19th-century and some 20th-century approaches to socioculture aimed to provide models for the evolution of humankind as a whole, arguing that different societies have reached different stages of social development. The most comprehensive attempt to develop a general theory of social evolution centering on the development of sociocultural systems, the work of Talcott Parsons (1902–1979), operated on a scale which included a theory of world history. Another attempt, on a less systematic scale, originated from the 1970s with the world-systems approach of Immanuel Wallerstein (1930–2019) and his followers.

Theotônio dos Santos Junior (11 November 1936 in Carangola – 27 February 2018 in Rio de Janeiro) was a Brazilian economist. He was one of the formulators of the Dependency Theory and supported the World-System theory.

Dos Santos had a bachelor's degree in sociology and politics in public administration from the Federal University of Minas Gerais and a master's degree in political science from the University of Brasília. He received the title of notório saber (equivalent to a doctorate) in economics from the Federal University of Minas Gerais and the Fluminense Federal University, at the latter of which he was Professor Emeritus. He coordinated for both the UNESCO Chair in Cultural Policies and Cooperation and the United Nations University in global economy and sustainable development.

In world-systems theory, periphery countries are those that are less developed than the semi-periphery and core countries. These countries usually receive a disproportionately small share of global wealth. They have weak state institutions and are dependent on—and, according to some, exploited by—more developed countries. These countries are usually behind because of obstacles such as lack of technology, unstable government, and poor education and health systems. In some instances, the exploitation of periphery countries' agriculture, cheap labor, and natural resources aid core countries in remaining dominant. This is best described by dependency theory, which is one theory on how globalization can affect the world and the countries in it. It is, however, possible for periphery countries to rise out of their status and move into semi-periphery or core status. This can be done by doing things such as industrializing, stabilizing the government and political climate, etc.

Janet Lippman Abu-Lughod (August 3, 1928 – December 14, 2013) was an American sociologist who made major contributions to world-systems theory and urban sociology.

The global language system is the "ingenious pattern of connections between language groups". Dutch sociologist Abram de Swaan developed this theory in 2001 in his book Words of the World: The Global Language System and according to him, "the multilingual connections between language groups do not occur haphazardly, but, on the contrary, they constitute a surprisingly strong and efficient network that ties together – directly or indirectly – the six billion inhabitants of the earth." The global language system draws upon the world system theory to account for the relationships between the world's languages and divides them into a hierarchy consisting of four levels, namely the peripheral, central, supercentral and hypercentral languages.