Chapter 1: Introduction to the Study of Language Development

Language and the Scientific Study of Language Development

• Definition of Language: Language is a systematic and conventional use of sounds, signs, or written symbols for communication or self-expression.
• Complexity: Language is multifaceted; learning it involves recognizing and producing sounds, combining them into words, and understanding vocabulary with its meanings and combinations.
  • Example: Knowing the difference between give and donate and how they combine with other words to form sentences.
• Components of Language:
  • Phonology: The sound system of a language.
    • Example: Ability to distinguish between $/vat/$ and $/bat/$, recognizing that $/narg/$ could be an English word but $/ngar/$ could not.
  • Lexicon: Vocabulary and associated knowledge.
    • Example: Knowing the meaning of words and how to form new words (e.g., if narg is a verb, then a narger is someone who nargs).
  • Morphology: The system for combining units of meaning.
  • Syntax: The system for combining words into sentences.
    • Example: Knowing the difference in meaning between Man bites dog and Dog bites man, knowing that Man bite dog and Bite man dog are both ungrammatical.
  • Pragmatics: Knowledge underlying the use of language to serve communicative functions.
    • Example: Being able to make requests, to comment, to be coherent in conversation and narrative.
  • Sociolinguistics: Knowledge that allows the socially appropriate use of language.
  • Literacy: Knowledge of reading and writing.
• Semantic Development: Learning a system for expressing meaning, often subsumed under word meaning and discussed in lexical development.

A Chronological Overview of Language Development

• Timeline: Language development milestones span from birth to 4 years and beyond.
  • Birth to 1 Year: Infants transition from cries to coos and babbles, showing comprehension by recognizing names around 6 months and understanding words by 8-10 months.
  • Second Year: Vocabulary expands rapidly; children produce their first words and, by year-end, have about 300 words; articulation develops.
  • Third Year: Grammar improves, with children producing two- and three-word sentences initially and progressing to full sentences.
  • 3 to 4 Years: Refinement of existing skills, complex sentences emerge, and language acquisition is largely completed, though skills continue to develop.
• Continued Growth: Language skills continue to grow after age 4 in articulation, vocabulary, sentence structure, and communicative skills.

Reasons for the Scientific Study of Language Development

• Basic Research Topic:
  • Understanding language acquisition provides insights into how the human mind works; language acquisition serves as a test for theories of behavioral change.
  • Cognitivism vs. Behaviorism: The field emerged in the 1950s when language acquisition became a battleground between behaviorism and cognitivism.
    • Behaviorism: Proposed that behavior changes due to consequences of prior behavior, without needing to understand the mind.
    • Cognitivism: Asserted that understanding behavior requires understanding internal mental processes.
  • Cognitive Revolution: Studies of language played a key role, showcasing the complexity of language acquisition beyond simple reinforcement models.
  • Cognitive Science: The interdisciplinary field emerged post the cognitive revolution, focusing on understanding how the mind works, with language acquisition as a central debate.
• Applied Research Topic:
  • Verbal skills are crucial for success; research focuses on addressing language skill disparities in minority and lower socioeconomic children.
  • Multilingualism: Research explores how children acquire competence in multiple languages, addressing educational challenges for multilingual children.
  • Language Acquisition Difficulties: Research focuses on understanding problems underlying language difficulty in children with conditions like mental retardation, hearing impairment, or brain injury.
• Points of Contact:
  • Basic research informs interventions for language difficulties.
  • Research on language disorders informs basic research.
    • Example: Studies on children with autism suggest language learning involves more than communication needs.
  • Interdisciplinary connections exist between anthropologists, psychologists, etc. to study language development.
    • Example: Anthropological descriptions of cultures without infant-directed speech inform developmental psychologists’ study of mother-infant interactions.

The History of the Study of Language Development

• Big Questions and Studies of Special Cases:
  • Language in the Brain: Early experiment by King Psammetichus aimed to find the original human race by raising children in isolation.
    • Modern parallel: Susan Goldin-Meadow's study of gestural communication invented by deaf children, indicating an innate ability to combine symbols.
  • "Wild Children" and the Nature of Humankind: Cases like the wild boy of Aveyron and Genie were studied to understand the intrinsic nature of humans, debating innate knowledge vs. societal influence.
    • The wild boy of Aveyron, studied by Dr. Jean-Marc Itard, yielded insights into training methods for the deaf.
    • Genie: Her case suggested a possible critical period for language acquisition.
• Baby Biographies:
  • Charles Darwin and others kept detailed records of their own children’s language development.
  • Diary studies continue among child language researchers.
• Normative Studies:
  • Between World War I and 1950s, research focused on describing norms for articulation, vocabulary size, and sentence length.
• The Chomskyan Revolution:
  • Chomsky’s Syntactic Structures (1957) changed linguistics by focusing on the mental grammar underlying what speakers do.
  • Roger Brown's studies of Adam, Eve, and Sarah marked the beginning of the Chomskyan era in child language research.
  • Research expanded from grammar to semantics, word meanings, pragmatics, and sociolinguistics.
• The Current Study of Language Development:
  • Includes a wider range of topics, populations, and methods, such as brain imaging, genomics, computer simulations, bilingual development, and literacy.
  • Cross-cultural and cross-linguistic research is central.

Current Approaches

• Language Socialization: Views language development as learning to communicate in one's social or cultural group.
• Language Acquisition Device (LAD):
  • Language acquisition is a device in the human brain that takes input from the environment and produces the ability to speak and understand a language.
  • Everything part of adult language knowledge must be in the input, internal device, or result from how the device operates on the input.
• Four Approaches:
  • Biological Approach: Understands language development as a biological phenomenon.
  • Linguistic Approach: Describes the child’s innate linguistic knowledge; seeks to describe Universal Grammar (UG).
  • Social Approach: Describes social processes that produce language acquisition.
  • Domain-General Cognitive Approach: Views language acquisition as a learning problem, with children using domain-general processes.
• Dynamical Systems Approach (DST): Rejects static knowledge; language emerges from continuous interaction of the system's components and the environment.
  • Example: Errors in naming familiar objects occur when vocabularies are expanding rapidly, reflecting an underlying dynamic system.
• Learnability Approach: Focuses on explaining the fact that language is acquired (i.e., that language is learnable).
• Developmental Approach: Focuses on explaining the course of language development.

Major Issues in the Field of Language Development

• Is It Nature or Nurture?
  • Debate on whether language development results from innate endowment or nurturing circumstances.
    • Empiricism: Claims the mind is a blank slate at birth; knowledge comes from experience.
    • Nativism: Asserts that knowledge cannot come from experience alone; the mind has preexisting structure.
  • Interactionism: Acknowledges innate characteristics but emphasizes children’s language-learning experiences.
    • Social Interactionism: Emphasizes social interaction in language acquisition.
    • Constructivism: Language is constructed using inborn mental equipment and environmental information.
  • Emergentism: Knowledge arises from interaction of biology and environment, often in the context of connectionist models.
• What Is the Nature of Nature?
  • Knowledge itself is innate, or the computational procedures for learning are innate, with knowledge resulting from these procedures.
  • Language-Specific Module:
    • The notion that children have inborn knowledge of the general form of language.
    • Modularity Thesis: The innate ability to develop language is a self-contained module in the mind.
  • Alternatives to Language-Specific Innateness:
    • Domain-general capacities may contribute to language acquisition (symbolic representation, memory skills, speech segmentation, pattern analysis).
    • Connectionism: Models how knowledge is represented in the brain, involving nodes and interconnections.
• What Kind of Learning Mechanisms Does the Child Have?
  • Babies as Statistical Learners: 8-month-olds can learn patterns in language by counting the frequency with which one stimulus is followed by another.
  • Babies as Rule Learners: 7-month-olds can learn rules (e.g., ABA pattern), but it’s debated whether this requires rule learning.
• What Kind of Knowledge Does the Child Acquire?
  • Linguistic knowledge consists of rules operating over symbols (traditional view).
  • Connectionist views propose linguistic processing without symbolic rule systems, with learning consisting of setting weights on connections.
• Is There Continuity or Discontinuity in Development?
  • Whether changes in language knowledge are continuous (acquiring more of the same kind of thing) or discontinuous (changes in kind).
• What Is the Relation between Communication and Language?
  • Formalism: The nature of language and its acquisition has nothing to do with communication.
  • Functionalism: Language and its acquisition are shaped and supported by communicative functions.
    • Communication explains the why of language development, the desire to communicate one’s thoughts and feelings to others is the motivation for language acquisition.

Theories of Language Development

• Generativist
  • Constructivist
  • Social interactionist
  • Connectionist
  • Behaviorist (primarily of historical interest; inadequate due to Chomsky's critique).

Methods of Research in Language Development

• Cross-Cultural and Cross-Linguistic Research:
  • Crucial for discovering universal processes of language acquisition; insights into individual differences and varied language-learning tasks.
• Research Designs:
  • Longitudinal and cross-sectional observational studies, correlational studies, experiments, computer simulations, and case studies.
• Assessment of Productive Language from Speech Samples:
  • Speech Sample Collection: Video or audio recordings of spontaneous speech samples.
    • Researchers pick settings where children are likely to talk (mealtime, toy play).
    • Representative samples are critical; 50 utterances are a minimum acceptable speech sample size.
    • Elicited production techniques (e.g., storytelling using picture books).
  • Speech Sample Transcription: Transcribing records; time-consuming but essential.
  • Transcript Coding and Analysis: Involves identifying and categorizing elements in the speech samples; turned into numbers for analysis; aided by computer programs (CHILDES, SALT, PEPPER, LIPP).
• CHILDES - A Data Archive:
  • Computer-based transcripts allow widespread data sharing; the CHILDES project has archive of transcripts of children’s speech in over 30 languages.
• Standardized Tests and Measures of Language Development:
  • Used to describe a child’s language in terms that compare to other children of the same age; measures often used for diagnosis and treatment evaluation.
  • Caregiver report instruments (e.g., MacArthur–Bates Communicative Development Inventories).
  • Examiner-administered instruments (e.g., Peabody Picture Vocabulary Test).
• Computational Modeling:
  • Tests theories of language acquisition by implementing them as computer programs.

Sources for Research on Language Development

• Journals:
  • Developmental psychology journals.
  • Cognitive psychology journals.
  • Linguistics journals.
  • Psycholinguistics journals.
  • Language development journals.
  • Language disorders journals.
  • Neuroscience journals.
  • Second language learning journals.
  • Other specialized journals.
• Indexes:
  • PsycINFO.
  • Linguistics and Language Behavior Abstracts.