Understanding spatial relations: flexible infants, lexical adults.

Concepts of containment, support, and degree of fit were investigated using nonverbal, preferential-looking tasks with 9- to 14-month-old infants and adults who were fluent in either English or Korean. Two contrasts were tested: tight containment vs. loose support (grammaticized as 'in' and 'on' in English by spatial prepositions and 'kkita' and 'nohta' in Korean by spatial verbs) and tight containment vs. loose containment (both grammaticized as 'in' in English but separately as 'kkita' and 'nehta' in Korean). Infants categorized both contrasts, suggesting conceptual readiness for learning such spatial semantics in either language. English-speaking adults categorized tight containment vs. loose support, but not tight vs. loose containment. However, Korean-speaking adults were successful at this latter contrast, which is lexicalized in their language. The adult data suggest that some spatial relations that are salient during the preverbal stage become less salient if language does not systematically encode them.