Why study individual differences?● Nativist approach: all children are the same, and studying one or two gives you an insight into the general process● But...large differences even in these very small-scale studies. some children are clearly precocious, and some children are “garden-variety” late talkers● Nativist approach: looking at how children acquire english gives you an insight into how all other languages are acquired● But...sizable cross-linguistic-\ differences in acquisition patterns● Looking at individual differencesTypes of Individual Differences● Rate of acquisition○ Some children are faster● Manner of acquisition○ Different children acquire different aspects of language firstSpeech Segmentation: Analytic vs Gestalt Children● Word babies vs Tune babies● Analytic children = acquire sounds and syllables● Gestalt children = acquire longer, phraselike units (frozen phrases), and not individual words (the 2-3 word utterances are learned as a unit, and are used as a unit); attend to prosodic cues● Both involve segmentation, but the unit of segmentation differsWord Learning: Expressive vs. Referential Children● Referential children = focus is on objects (nouns predominate)● Expressive children = focus is on people (pronouns, function words, and social expressions predominate)● This difference may reflect differences in cognitive styles: referential children think that language is for organizing objects and for talking about objects; expressive children thinkthat● Some difficulties with the expressive/referential distinction: often based on parental reports, word-sage varies with context, frequency of use vs number of words; not a dichotomy but a continuumGrammatical Development: Nominal vs Pronominal Children● Nominal children = combine two content words● Pronominal children = combine a function word with a content word (“I go”, “sit down”)● Children with similar MLUs may have very different grammatical structures● Seems to follow the word learning differences, with referential children becoming nominal, and expressive children becoming pronominal● Seems to also be related to speech segmentation differences, with “word babies” abstracting words and “tune babies” encoding larger phrasal unitsWhy are there individual differences in language development?● Child factors○ Temperament: shy children vs outgoing children○ Cognitive skills: Perception, attention, memory○ Gender: girls vs boys● Environmental factors○ Maternal speech: some mothers refer to others and use language○ SES and parental education levels○ Cross-linguistic differencesPhonological Development: Cautious Children vs Risk-Takers● Cautious children = use consistent phonological rules (so that the intended word is easy to decipher); if cannot produce a word according to these rules, will avoid the word● Risk takers = do not use consistent phonological rules (sloppy), apply rules optionally; trynew words easily Differences in Cognitive Skills● Perceptual acuity● Attention and memory● Metalinguistic/Metacognitive awarenessPerceptual Acuity● Auditory processing● One of the skill critical to the acquisition of language is the ability to process and categorize brief, rapidly changing auditory signals (signals that occur within tens of milliseconds). These acoustic cues are critically important for identifying and distinguishing sound transitions in speech● Some evidence that RAP (Rapid Auditory Processing) is predictive of speech and language developmentAttention and Memory● Joint attention, selective attention, and sustained attention are all important for learning language○ E.g., being able to engage in joint attention is predictive of vocabulary size 1 yearlater○ E.g., children with ADD frequently have speech-and-language difficulties, as well● Memory skills are predictive of word-learning○ E.g., being able to repeat a word at age 2 is predictive of vocabulary size 1 year laterMetalinguistic Awareness● Knowledge about the nature of language○ E.g., knowledge that the name of the object is separable from the object itself■ Word-Size Tasks● Big word = big object (hippopotamus is big, and the word is big)● Big word = small object (dragonfly is small, but the word is big)● Metalinguistic awareness develops over a period of several years (~middle school)● Metalinguistic awareness predicts syntactic development, and children’s ability to acquire literacyGender Differences in Language Use● “Men are from Mars…”● Gender differences can be observed as early as at 3 yrs of age○ Girls tend to begin speaking before boys○ Girls tend to have a higher vocabulary and produce more 2 word utterances (andhave larger MLUs)○ Recent work: girls maily use a sustem that is based around memorizing words and association between them; boys rely primarily on a system that governs the rules of language■ Girls over-regularize more than boys● Are these differences innate or socio-cultural?● Sex differences○ Most of the cognitive changes involved in language acquisition take place in girls between about 14 and 20 months of age. These same changes usually don’t appear in boys until 20-24 months of age● Gender differences○ Parents treat children differently based on the sex of the baby. Parents talk more with baby girls than with baby boys. Fathers play more with their sons and engage in more rough and tumble play. Fathers encourage interpersonal interactions and communication skills in their daughtersDifferences in the Input● Differnet parental styles, different developmental trajectories; different contexts of learning, different outcomes○ E.g., mothers use nouns in descriptions → more nouns in children’s first 50 words; mothers interact via social routines → more social expressions in children’s utterances○ May be a mutually-reinforcing process, whereby a child’s style invites the specifictype of parental input● Interactive environment vs non-interactive environment (e.g., playing with blocks vs. watching TV)● Different languages, different developmental trajectories○ E.g., nouns vs verbs in early