Chapter 6 - Development of Language and Symbol Use
• Systems for representing thoughts, feelings, and knowledge and communicating
them to others
• The creative and flexible use of symbols is the capacity that most sets humans
apart from other species
• Sociocultural Context
• Individual Differences
• TheActive Child
I. Language Development
II. Nonlinguistic Symbols and Development
• By 5 years of age, children have mastered the basic structure of their native language,
whether spoken or manually signed.
Using Language Involves...
• Language comprehension: Refers to understanding what others say (or sign or
• Language production: Refers to actually speaking (or signing or writing) to others
The Components of Language
• Generativity: using the finite set of words in our vocabulary, we can put together
an infinite number of sentences and express an infinite number of ideas
Required Competencies for Learning Language
• Phonological development: the acquisition of knowledge about phonemes, the
elementary units of sound that distinguish meaning
• Semantic development: learning the system for expressing meaning in a language,
beginning with morphemes, the smallest unit of meaning in a language
• Syntactic development: learning the syntax or rules for combining words
• Pragmatic development: acquiring knowledge of how language is used, which
includes understanding a variety of conversational conventions
1 • Phonology: System of sounds
• Phonemes: Basic units of sound
• Can change meaning
E.g., /b/ at → /c/ at
E.g., b /a/ t → b /i/ t
• English contains between 40-45 phonemes
• Morphemes: the smallest units of speech that are meaningful (e.g., dog and
Free morphemes: dog
Bound morphemes: -s or re
Syntax: the set of rules of language by which we construct sentences.
• Rules for word combinations
Garfield Odie bit.
Garfield bit Odie.
Odie bit Garfield.
• Using language to communicate effectively
• Verbal aspects
• Sociolinguistic knowledge
• Nonverbal aspects (e.g., facial expression, body language)
• Paralinguistic aspects (e.g., loudness and intonation)
What Is Required for Language?
• What does it take to be able to learn a language in the first place?
• Full-fledged language is achieved only by humans, but only if they have
experience with other humans using language for communication.
• The key to full-fledged language development is in the human brain:
• Language is a species-specific behavior
o Only humans acquire a communication system with the complexity,
structure, and generativity of language.
• Language is also species-universal:
Virtually all humans develop language
2 • Although some nonhuman primates have been trained to use signs or other
symbols after concentrated effect by humans, there appears to be little evidence
that they have acquired syntax.
• Language processing involves a substantial degree of functional localization in
• The left hemisphere shows some specialization for language in infancy, although
the degree of hemispheric specialization for language increases with age.
• Studies of individuals with brain damage resulting in aphasia provide
evidence of specialization for language within the left hemisphere.
• Damage to Broca’s area, near the motor cortex, is associated with
difficulties in producing speech.
• Damage to Wernicke’s area, which is near the auditory cortex, is linked
to difficulties with meaning.
Critical Period for Language Development
• To learn language, children must also be exposed to other people using language
—spoken or signed.
• Sometime between age 5 and puberty, language acquisition becomes much more
difficult and ultimately less successful.
• Critical (sensitive) period
• Time when child is sensitive to particular stimuli
• Feral children
• “Wild boy ofAveyron” or Victor
• Discovered at 11 or 12 years of age
• Discovered at 13 years of age
Test of the Critical-Period Hypothesis
• Performance on a test of English grammar by adults originally from Korea and
China was directly related to the age at which they came to the United States and
were exposed to English.
• The scores of adults who emigrated before the age of 7 are indistinguishable from
those of native English speakers.
• Infant-directed talk (IDT) is the distinctive mode of speech that adults adopt when
talking to babies and very young children.
3 • It is common throughout the world, but it is not universal
• Its characteristics include a warm and affectionate tone, high pitch, extreme
intonation, and slower speech accompanied by exaggerated facial expressions
• Infants prefer IDT to speech directed to adults.
The Process of LanguageAcquisition
• Acquiring a language involves both comprehending what other people
communicate to you and producing language of your own.
• Infants know a great deal about language long before their first linguistic
Categorical Perception of Speech Sounds
• Both adults and infants possess categorical perception of speech sounds (the
perception of speech sounds as belonging to discrete categories).
• The two phonemes /b/ and /p/ occur along an acoustic continuum except that they
differ in voice onset time (VOT)--the length of time between when air passes
through the lips and when the vocal cords start vibrating.
Categorical Perception of Speech byAdults
• When adults listen to a tape of artificial speech sounds that gradually change from
one sound to another, such as /ba/ to /pa/ or vice versa, they suddenly switch from
perceiving one sound to perceiving the other.
Categorical Perception of Speech by Infants
• The baby has learned to turn his head to the sound source whenever he hears a change
from one sound to another.
• Acorrect head turn is rewarded by an exciting visual display, as well as by the
applause and praise of the experimenter.
Developmental Changes in Speech Perception
• Infants’ability to discriminate between speech sounds not in their native language
declines between 6 and 12 months of age.
• Six-month-olds from English-speaking families readily discriminate between
syllables in Hindi (blue bars) and Nthlakapmx (green bars), but 10- to 12-month-olds
Sensitivity to Regularities in Speech
• In addition to focusing on the speech sounds that are used in their native language,
infants become increasingly sensitive to many of the numerous regularities in that
• Stress patterns: an element of prosody
• Distributional properties: in any language, certain sounds are more likely to appear
together than are others
4 • Their own name: as early as 5 months they show the “cocktail party effect”
• Sometime between 6 and 10 months of age, infants begin to babble by repeating
strings of sounds comprising a consonant followed by a vowel.
• Akey component of the development of babbling is receiving feedback about the
sounds one is producing.
• Congenitally deaf babies’vocal babbling occurs late and is very limited, unless they
are exposed to sign language, in which case they produce repetitions of hand
movements that are components ofASL signs in a manner analogous to vocal
babbling among hearing infants.
• As infants’babbling becomes more varied, it conforms more to the sounds, rhythm,
and intonation patterns of the language they hear daily.
• Babies who are exposed to the sign language of their deaf parents engage in
• Asubset of their hand movements differ from those of infants exposed to spoken
language in that their slower rhythm corresponds to the rhythmic patterning of adult
• Even before infants start speaking, they develop interactive routines similar
to those required in the use of language for communication.
o Turn taking: apparent in simple games like “Give-and-Take”
o Intersubjectivity: the sharing of a common focus of attention by two or
o Joint attention: established when th