At around 1 year of age, human infants display a number of new behaviors that seem to indicate a newly emerging understanding of other persons as intentional beings whose attention to outside objects may be shared, followed into, and directed in various ways. These behaviors have mostly been studied separately. In the current study, we investigated the most important of these behaviors together as they emerged in a single group of 24 infants between 9 and 15 months of age. At each of seven monthly visits, we measured joint attentional engagement, gaze and point following, imitation of two different kinds of actions on objects, imperative and declarative gestures, and comprehension and production of language. We also measured several nonsocial-cognitive skills as a point of comparison. We report two studies. The focus of the first study was the initial emergence of infants' social-cognitive skills and how these skills are related to one another developmentally. We found a reliable pattern of emergence: Infants progressed from sharing to following to directing others' attention and behavior. The nonsocial skills did not emerge predictably in this developmental sequence. Furthermore, correlational analyses showed that the ages of emergence of all pairs of the social-cognitive skills or their components were inter-related. The focus of the second study was the social interaction of infants and their mothers, especially with regard to their skills of joint attentional engagement (including mothers' use of language to follow into or direct infants' attention) and how these skills related to infants' early communicative competence. Our measures of communicative competence included not only language production, as in previous studies, but also language comprehension and gesture production. It was found that two measures--the amount of time infants spent in joint engagement with their mothers and the degree to which mothers used language that followed into their infant's focus of attention--predicted infants' earliest skills of gestural and linguistic communication. Results of the two studies are discussed in terms of their implications for theories of social-cognitive development, for theories of language development, and for theories of the process by means of which human children become fully participating members of the cultural activities and processes into which they are born.

Social Cognition, joint attention and communicative Competence from 9 to 15 months of age

How social contexts support and shape language development

Motor function involves complex physiologic processes and requires the integration of multiple systems, including neuromuscular, musculoskeletal, and cardiopulmonary, and neural motor and sensory-perceptual systems. Motor-functional status is indicative of current physical health status, burden of disease, and long-term health outcomes, and is integrally related to daily functioning and quality of life. Given its importance to overall neurologic health and function, motor function was identified as a key domain for inclusion in the NIH Toolbox for Assessment of Neurological and Behavioral Function (NIH Toolbox). We engaged in a 3-stage developmental process to: 1) identify key subdomains and candidate measures for inclusion in the NIH Toolbox, 2) pretest candidate measures for feasibility across the age span of people aged 3 to 85 years, and 3) validate candidate measures against criterion measures in a sample of healthy individuals aged 3 to 85 years (n = 340). Based on extensive literature review and input from content experts, the 5 subdomains of dexterity, strength, balance, locomotion, and endurance were recommended for inclusion in the NIH Toolbox motor battery. Based on our validation testing, valid and reliable measures that are simultaneously low-cost and portable have been recommended to assess each subdomain, including the 9-hole peg board for dexterity, grip dynamometry for upper-extremity strength, standing balance test, 4-m walk test for gait speed, and a 2-minute walk test for endurance.

https://n.neurology.org/content/neurology/80/11_Supplement_3/S54.full.pdf

Cognition assessment using the NIH Toolbox

This prospective longitudinal study examined the contribution of dimensions of maternal responsiveness (descriptions, play, imitations) to the timing of five milestones in children's (N = 40) early expressive language: first imitations, first words, 50 words in expressive language, combinatorial speech, and the use of language to talk about the past. Events-History Analysis, a statistical technique that estimates the extent to which predictors influence the timing of events, was used. At 9 and 13 months, maternal responsiveness and children's activities (e.g., vocalizations, play) were coded from videotaped interactions of mother-child free play; information about children's language acquisition was obtained through biweekly interviews with mothers from 9 through 21 months. Maternal responsiveness at both ages predicted the timing of children's achieving language milestones over and above children's observed behaviors. Responsiveness at 13 months was a stronger predictor of the timing of language milestones than was responsiveness at 9 months, and certain dimensions of responsiveness were more predictive than others. The multidimensional nature of maternal responsiveness and specificity in mother-child language relations are discussed.

https://www.jstor.org/stable/info/1132453

Maternal responsiveness and children's achievement of language milestones.

This study investigated predictors of growth in toddlers’ vocabulary production between the ages of 1 and 3 years by analyzing mother–child communication in 108 low-income families. Individual growth modeling was used to describe patterns of growth in children’s observed vocabulary production and predictors of initial status and between-person change. Results indicate large variation in growth across children. Observed variation was positively related to diversity of maternal lexical input and maternal language and literacy skills, and negatively related to maternal depression. Maternal talkativeness was not related to growth in children’s vocabulary production in this sample. Implications of the examination of longitudinal data from this relatively large sample of low-income families are discussed.

/pdf/maternal-correlates-of-growth-in-toddler-vocabulary-2y7ly2o461.pdf

Maternal correlates of growth in toddler vocabulary production in low-income families.

Data from parent reports on 1,803 children--derived from a normative study of the MacArthur Communicative Development Inventories (CDIs)--are used to describe the typical course and the extent of variability in major features of communicative development between 8 and 30 months of age. The two instruments, one designed for 8-16-month-old infants, the other for 16-30-month-old toddlers, are both reliable and valid, confirming the value of parent reports that are based on contemporary behavior and a recognition format. Growth trends are described for children scoring at the 10th-, 25th-, 50th-, 75th-, and 90th-percentile levels on receptive and expressive vocabulary, actions and gestures, and a number of aspects of morphology and syntax. Extensive variability exists in the rate of lexical, gestural, and grammatical development. The wide variability across children in the time of onset and course of acquisition of these skills challenges the meaningfulness of the concept of the modal child. At the same time, moderate to high intercorrelations are found among the different skills both concurrently and predictively (across a 6-month period). Sex differences consistently favor females; however, these are very small, typically accounting for 1%-2% of the variance. The effects of SES and birth order are even smaller within this age range. The inventories offer objective criteria for defining typicality and exceptionality, and their cost effectiveness facilitates the aggregation of large data sets needed to address many issues of contemporary theoretical interest. The present data also offer unusually detailed information on the course of development of individual lexical, gestural, and grammatical items and features. Adaptations of the CDIs to other languages have opened new possibilities for cross-linguistic explorations of sequence, rate, and variability of communicative development.

Variability in Early Communicative Development

The MacArthur Communicative Development Inventories (CDIs) are a pair of widely used
 parent-report instruments for assessing communicative skills in infants and toddlers. This report
 describes short-form versions of the CDIs and their development, summarizes newly available
 normative data and psychometric properties of the instruments, and discusses research and
 clinical applications. The infant short form (Level I, for 8- to 18-month-olds) contains an
 89-word checklist for vocabulary comprehension and production. The two parallel versions of
 the toddler short form (Level II, Forms A and B, for 16- to 30-month-olds) each contain a
 100-word vocabulary production checklist and a question about word combinations. The forms
 may also be useful with developmentally delayed children beyond the specified age ranges.
 Copies of the short forms and the normative tables appear in the appendices.

/pdf/short-form-versions-of-the-macarthur-communicative-5c1f8ormmn.pdf

Short-form versions of the MacArthur Communicative Development Inventories.

The MacArthur Communicative Development Inventories (CDIs) are a pair of widely used parentreport instruments for assessing communicative skills in infants and toddlers. This report describes short-form versions of the CDIs and their development, summarizes newly available normative data and psychometric properties of the instruments, and discusses research and clinical applications. The infant short form (Level I, for 8to 18-month-olds) contains an 89-word checklist for vocabulary comprehension and production. The two parallel versions of the toddler short form (Level II, Forms A and B, for 16to 30-month-olds) each contain a 100-word vocabulary production checklist and a question about word combinations. The forms may also be useful with developmentally delayed children beyond the specified age ranges. Copies of the short forms and the normative tables appear

Steve Pethick

Papers

Variability in Early Communicative Development

Short-form versions of the MacArthur Communicative Development Inventories.

Normative data for the short form versions of the Macarthur communicative development inventories