Many bilingual speakers believe they engage in different forms of thinking when they shift languages. This experience of entering different thought worlds can be explained with the hypothesis that languages induce different forms of ‘thinking-for-speaking’ – thinking generated, as Slobin (1987) says, because of the requirements of a linguistic code. “‘Thinking for speaking’ involves picking those characteristics that (a) fit some conceptualization of the event, and (b) are readily encodable in the language” (p. 435). That languages differ in their thinking-for-speaking demands is a version of the linguistic relativity hypothesis, the proposition that language influences thought and that different languages influence thought in different ways.
Thinking-for-speaking differs from the so-called strong Whorfian version of the linguistic relativity hypothesis, as we understand it. The latter (Whorf 1956; Lucy & Wertsch 1987; Lucy 1992a, b) refers to general, langue-wide patterns of ‘habitual thought’, patterns that, according to the hypothesis, are embodied in the forms of the language and analogies among them. The thinking-for-speaking hypothesis, in contrast, refers to how speakers organize their thinking to meet the demands of linguistic encoding on-line, during acts of speaking – what Saussure (1959) termed parole rather than langue. The thinking-for-speaking version and the Whorfian version of the linguistic relativity hypothesis are not mutually exclusive, but neither are they identical. The distinction between them parallels the characterization of Whorf as ‘synchronic’ compared with Vygotsky (1987) as ‘diachronic’ that was offered by Lucy & Wertsch (1987). Following them, we will regard the thinking-for-speaking hypothesis as having a diachronic focus on thinking rather than a synchronic focus on habitual thought.