One language, Interlingua, was developed so that the languages of Western civilization would act as its dialects. Drawing from such concepts as the international scientific vocabulary and Standard Average European, linguists[who?] developed a theory that the modern Western languages were actually dialects of a hidden or latent language.[citation needed] Researchers at the International Auxiliary Language Association extracted words and affixes that they considered to be part of Interlingua's vocabulary. In theory, speakers of the Western languages would understand written or spoken Interlingua immediately, without prior study, since their own languages were its dialects. This has often turned out to be true, especially, but not solely, for speakers of the Romance languages and educated speakers of English. Interlingua has also been found to assist in the learning of other languages. In one study, Swedish high school students learning Interlingua were able to translate passages from Spanish, Portuguese, and Italian that students of those languages found too difficult to understand. It should be noted, however, that the vocabulary of Interlingua extends beyond the Western language families.

What language could all Western languages be considered dialects of?