stated a formal hypothesis, Brown and Lenneberg formulated their own. Their two tenets were (i) "the world is differently experienced and conceived in different linguistic communities" and (ii) "language causes a particular cognitive structure". Brown later developed them into the so-called "weak" and "strong" formulation: Structural differences between language systems will, in general, be paralleled by nonlinguistic cognitive differences, of an unspecified sort, in the native speakers of the language. The structure of anyone's native language strongly influences or fully determines the worldview he will acquire as he learns the language. Brown's formulations became widely known and were retrospectively attributed to Whorf and Sapir although the second formulation, verging on linguistic determinism, was never advanced by either of them. Joshua Fishman's "Whorfianism of the third kind" Joshua Fishman argued that Whorf's true position was largely overlooked. In 1978, he suggested that Whorf was a "neo-Herderian champion" and in 1982, he proposed "Whorfianism of the third kind" in an attempt to refocus linguists' attention on what he claimed was Whorf's real interest, namely the intrinsic value of "little peoples" and "little languages". Whorf had criticized Ogden's Basic English thus: Where Brown's weak version of the linguistic relativity hypothesis proposes that language influences thought and the strong version that language determines thought, Fishman's "Whorfianism of the third kind" proposes that language is a key to culture. Leiden School The Leiden School is a linguistic theory that models languages as parasites. Notable proponent Frederik Kortlandt, in a 1985 paper outlining Leiden School theory, advocates for a form of linguistic relativity: "The observation that in all Yuman languages the word for ‘work’ is a loan from Spanish should be a major blow to any current economic theory." In the following paragraph, he directly quotes from Sapir: "Even in the most primitive cultures the strategic word is likely to be more powerful than the direct blow." Rethinking Linguistic Relativity The publication of the 1996 anthology Rethinking Linguistic Relativity edited by Gumperz and Levinson began a new period of linguistic relativity studies that focused on cognitive and social aspects. The book included studies on linguistic relativity and universalist traditions. Levinson documented significant linguistic relativity effects in the different linguistic conceptualization of spatial categories in different languages. For example, men speaking the Guugu Yimithirr language in Queensland gave accurate navigation instructions using a compass-like system of north, south, east and west, along with a hand gesture pointing