chapter summary:

A critical feature of what it means to be human is the creative and flexible use of a variety of languages and other symbols. The enormous power of language comes from generativity—the fact that a finite set of words can be used to generate an infinite number of sentences.

Language Development

• Acquiring a language involves learning the complex system of phonology, semantics, syntax, and pragmatics that govern its sounds, meaning, grammar, and use.
• Language ability is species-specific. The first prerequisite for its full-fledged development is a human brain. Researchers have succeeded in teaching nonhuman animals remarkable symbolic skills but not full-fledged language.
• The early years constitute a critical period for language acquisition; many aspects of language are more difficult to acquire thereafter.
• A second prerequisite for language development is exposure to language. Much of the language babies hear takes the form of infant-directed speech (IDS), which is characterized by a higher-than-normal pitch; extreme shifts in intonation; a warm, affectionate tone; and exaggerated facial expressions.
• Infants have remarkable speech-perception abilities. Like adults, they exhibit categorical perception of speech sounds, perceiving physically similar sounds as belonging to discrete categories.
• Young infants are actually better than adults at discriminating between speech sounds not in their native language. As they learn the sounds that are important in their language(s), infants’ ability to distinguish between sounds in other languages declines.
• Infants are remarkably sensitive to the distributional properties of language; they notice a variety of subtle regularities in the speech they hear and use these regularities to segment words from fluent speech.
• Infants begin to babble at around 7 months of age, either repeating syllables (“bababa”) or, if exposed to sign language, using repetitive hand movements. Gradually, vocal babbling begins to sound more like the baby’s native language.
• During the second half of the first year, infants are learning how to interact and communicate with other people, including developing the ability to establish joint attention.
• Infants begin to recognize highly familiar words at about 6 months of age.
• Infants begin to produce words at around 1 year of age. They initially say just one word at a time, and often make overextension errors, using a particular word in a broader context than is appropriate. Infants make use of a variety of strategies to figure out what new words mean.
• By the end of their second year, most infants produce short sentences. The length and complexity of their utterances gradually increase, and infants spontaneously practice their emerging linguistic skills.
• In the early preschool years, children exhibit generalization, extending such patterns as “add–s to make plural” to novel nouns, and making overregularization errors.
• Children develop their burgeoning language skills as they go from collective monologues to sustained conversation, improving their ability to tell coherent narratives about their experiences.
• All current theories of language development agree that there is an interaction between innate factors and experience.
• Nativists, such as the influential linguist Noam Chomsky, posit innate knowledge of “Universal Grammar,” the set of highly abstract rules common to all languages. They believe that language learning is supported by language-specific skills.
• Theorists focused on social interaction emphasize the communicative context of language development and use. They emphasize the impressive degree to which infants and young children exploit a host of pragmatic cues to figure out what others are saying.
• Other perspectives argue that language can develop in the absence of innate knowledge and that language learning requires powerful general-purpose cognitive mechanisms. Connectionist models have been used to support this view.

Nonlinguistic Symbols and Development

• Symbolic artifacts like maps or models require dual representation. To use them, children must represent mentally both the object itself as well as its symbolic relation to what it stands for. Toddlers become increasingly skillful at achieving dual representation and using symbolic artifacts as a source of information.
• Drawing is a popular symbolic activity. Young children’s early scribbling quickly gives way to the intention to draw pictures of something, with a favorite theme being representations of the human figure.