Opening a box a toddler says open; seeing a toy car in it she says car; taking the car out she says out; putting it on the floor she says down. In the world at large these little remarks do not command much attention. But to people interested in how children learn to talk, the first steps into language raise fascinating and difficult questions. In this chapter, we are concerned with the central puzzle of where children's early word meanings come from. Are they introduced through language? Do they reflect concepts that arise spontaneously through infants' perceptual and cognitive development? Do language and cognition interact to produce early word meanings, and, if so, how?

The idea that children learn how to structure meanings through exposure to language is usually associated with Whorf (1956). Whorf stressed that languages differ in the way they partition the world, and he proposed that in learning the semantic categories of their language, children also acquire a world view, a way of interpreting their experiences. Inspired by Whorf, Roger Brown also emphasized the role of the linguistic input in children's concept formation, arguing that a new word can be a “lure to cognition” (R. Brown 1958:206–7)- a recurrent signal that “serves to attract relevant experiences, to sum them over time into a conception governing the use of the word” (1965:311).