Language and thought over developmental time
Languages across the globe vary in how they classify experience. Do such variations in classification affect the way speakers consider their worlds, even when they are not speaking? Benjamin Lee Whorf (1956) first popularised the notion that linguistic classifications might influence, not only how one talks about the world, but also how one thinks about the world when not actually speaking. In other words, one might partition the world differently depending upon the language one speaks. This hypothesis remains intriguing, although it has proved surprisingly difficult to test (cf. Lucy, 1992a).
A particularly compelling example of the type of influence Whorf suggested was reported by Lucy (1992b), who explored the impact on thought of formal linguistic devices for marking number. Lucy began by analysing the distribution of these linguistic devices in two languages – Yucatec Mayan and American English – showing that different devices are used to mark different types of objects in both languages. For example, in both Yucatec and English, words for animals are marked by the plural (e.g., ‘two pigs’), while words for substances are not (e.g., one doesn't say ‘two muds’ in English unless referring to various types of mud). The two languages differ, however, in how they treat a third type of object – implements. In English, implements are marked by the plural, as are animals (e.g., ‘two rakes’, comparable to ‘two pigs’); in Yucatec, they are marked like substances. Thus, on linguistic grounds, implements are classified with animals in English but with substances in Yucatec.