Lusotropicalism or Luso-tropicalism was first described by Brazilian sociologist Gilberto Freyre to describe the distinctive character of Portuguese imperialism overseas, proposing that the Portuguese were better colonizers than other European nations.
It was believed that because of Portugal's warmer climate, and having been inhabited by Celts, Romans, Visigoths, Moors and several other peoples in pre-modern times, the Portuguese were more humane, friendly, and adaptable to other climates and cultures.
In addition, by the early 20th century, Portugal was by far the European colonial power with the oldest territorial presence overseas; in some cases its territories had been continuously settled and ruled by the Portuguese throughout five centuries. It celebrated both actual and mythological elements of racial democracy and civilizing mission in the Portuguese Empire, encompassing a pro-miscegenation attitude toward the colonies/overseas territories. It is best exemplified in the work of Gilberto Freyre.
Gilberto Freyre on the criticisms that he received
The life of Gilberto Freyre, after he published Casa-Grande & Senzala, became an eternal source of explanation. He repeated several times that he did not create the myth of a racial democracy and that the fact that his books recognized the intense mixing between "races" in Brazil did not mean a lack of prejudice or discrimination. He pointed out that many people have claimed the United States to have been an "exemplary democracy" whereas slavery and racial segregation were present throughout most of the history of the United States.
"The interpretation of those who want to place me among the sociologists or anthropologists who said prejudice of race among the Portuguese or the Brazilians never existed is extreme. What I have always suggested is that such prejudice is minimal (...) when compared to that which is still in place elsewhere, where laws still regulate relations between Europeans and other groups".
"It is not that racial prejudice or social prejudice related to complexion are absent in Brazil. They exist. But no one here would have thought of "white-only" Churches. No one in Brazil would have thought of laws against interracial marriage (...) Fraternal spirit is stronger among Brazilians than racial prejudice, colour, class or religion. It is true that equality has not been reached since the end of slavery (...) There was racial prejudice among plantation owners, there was social distance between the masters and the slaves, between whites and blacks (...) But few wealthy Brazilians were as concerned with racial purity as the majority were in the Old South". 
In order to support his colonial policies, António de Oliveira Salazar adopted Gilberto Freyre's notion of Lusotropicalism, maintaining that since Portugal had been a multicultural, multiracial and pluricontinental nation since the 15th century, if the country were to be dismembered by losing its overseas territories, that would spell the end for Portuguese independence. In geopolitical terms, no critical mass would then be available to guarantee self-sufficiency to the Portuguese State.
Salazar had strongly resisted Freyre's ideas throughout the 1930s, partly because Freyre claimed the Portuguese were more prone than other European nations to miscegenation, and adopted Lusotropicalism only after sponsoring Freyre on a visit to Portugal and some of its overseas territories in 1951-2. Freyre's work Aventura e Rotina (Adventure and Routine) was a result of this trip.
- Writing captivity in the early modern Atlantic: circulations of knowledge and authority in the Iberian and English imperial worlds Lisa Voigt 2009 page 15
- Miguel Vale de Almeida, Portugal’s Colonial Complex: From Colonial Lusotropicalism to Postcolonial Lusophony
- Castelo, Cláudia, O Modo Português de estar no Mundo' O luso-tropicalismo e a ideologia colonial portuguesa (1933–1961). Porto: Edições Afrontamento, 1999.
- Cahen, Michel, "'Portugal is in the Sky': Conceptual Considerations on Communities, Lusitanity and Lusophony", in E.Morier-Genoud & M.Cahen (eds), Imperial Migrations. Colonial Communities and Diaspora in the Portuguese World, London: Palgrave, 2012
- Nery da Fonseca, Edson. Em Torno de Gilberto Freyre. Recife: Editora Massangana, 2007.
- Nery da Fonseca, Edson. Gilberto Freyre de A a Z - Referências essenciais à sua vida e obra. Rio de Janeiro: Zé mario Editor, 2002.
- Vakil, Abdoolkarim, "'Mundo Pretuguês': Colonial and Postcolonial Diasporic Dis/articulations", in E.Morier-Genoud & M.Cahen (eds), Imperial Migrations. Colonial Communities and Diaspora in the Portuguese World, London: Palgrave, 2012
- Villon, Victor. O Mundo Português que Gilberto Freyre Criou - seguido de Diálogos com Edson Nery da Fonseca. Rio de Janeiro, Vermelho Marinho, 2010.