Your intro psychology class just hit the language development unit, and suddenly you're juggling Chomsky's Language Acquisition Device, overregularization errors, the critical period hypothesis, and Genie — all before Friday's exam. This guide cuts through the clutter.

**TLDR: Language Development in Childhood** is a focused, concise primer that walks you through exactly what psychologists know about how children move from birth cries to full sentences. Starting with the core components of language — phonology, syntax, semantics, and pragmatics — it tracks the predictable milestones from cooing and babbling through the two-word stage and telegraphic speech, all the way to complex grammar by age five.

The guide then compares the three major theories of child language acquisition: Skinner's behaviorist conditioning model, Chomsky's nativist argument for an innate grammar device, and the social-interactionist view that puts caregivers and context at the center. A dedicated section on evidence examines what overregularization errors reveal about grammar learning, what deprivation cases like Genie tell us about the critical period, and how deaf children spontaneously invent sign systems. The final section covers child-directed speech, joint attention, bilingual development, and cross-cultural differences — the real-world input side of the equation.

Written for high school and early college students, this is the AP psychology language development review you can read in one sitting and actually remember.

Pick it up and walk into your next exam knowing exactly what to say.

• Identify the major milestones of language development from birth through age five
• Distinguish between phonology, semantics, syntax, morphology, and pragmatics
• Compare nativist, learning-theory, and social-interactionist explanations of language acquisition
• Explain key evidence including the critical period, overregularization errors, and child-directed speech
• Apply these concepts to real cases such as bilingual children and language deprivation

1. 1. What Language Development Means
   Defines language, lays out its core components, and frames the central puzzle of acquisition.
2. 2. Milestones from Birth to Age Five
   Walks through the predictable sequence of stages: cooing, babbling, first words, two-word stage, telegraphic speech, and complex sentences.
3. 3. Theories of Language Acquisition
   Compares Skinner's behaviorist account, Chomsky's nativist Language Acquisition Device, and the social-interactionist view.
4. 4. Evidence from Errors, Critical Periods, and Deprivation
   Examines overregularization, the critical period hypothesis, deaf children inventing sign language, and cases like Genie.
5. 5. The Role of Input: Caregivers, Bilingualism, and Culture
   Looks at child-directed speech, joint attention, bilingual development, and cross-cultural variation in how adults talk to children.