Longitudinal Effects on Early Adolescent Language: A Twin Study.

Purpose: We evaluated genetic and environmental contributions to individual differences in language skills during early adolescence, measured by both language sampling and standardized tests, and examined the extent to which these genetic and environmental effects are stable across time.

Method: We used structural equation modeling on latent factors to estimate additive genetic, shared environmental, and nonshared environmental effects on variance in standardized language skills (i.e.

Impact of prematurity on language skills at school age.

Purpose: The existing literature on language outcomes in children born prematurely focuses almost exclusively on standardized test scores rather than discourse-level abilities. The authors of this study looked longitudinally at school-age language outcomes and potential moderating variables for a group of twins born prematurely versus a control group of twins born at full term, analyzing both standardized test results and language sample data from the population-based Western Reserve Reading Project (WRRP; Petrill, Deater-Deckard, Thompson, DeThorne, & Schatschneider, 2006).

Method: Fifty-seven children born prematurely, at ≤32 weeks or <1,500 g, were compared with 57 children born at full term and were matched for age, gender, race, and parental education.

Longitudinal stability in genetic effects on children's conversational language productivity.

Purpose: The authors examined the longitudinal stability of genetic and environmental influences on children's productive language sample measures during the early school-age years.

Method: Twin study methodology with structural equation modeling was used to derive univariate estimates of additive genetic (A), shared environmental (C), and nonshared environmental (E) effects on language measures at each of 2 time points, based on 487 twins at the 1st-grade time point and 387 twins at the 2nd-grade time point. To address questions of stability over time, the authors used longitudinal latent factor analysis.

Volubility as a mediator in the associations between conversational language measures and child temperament.

Background: Despite support for the use of conversational language measures, concerns remain regarding the extent to which they may be confounded with aspects of child temperament, extraversion in particular.

Aims: This study of 161 twins from the Western Reserve Reading Project (WRRP) examined the associations between children's conversational language use and three key aspects of child temperament: Surgency (i.e.

Conversational language use as a predictor of early reading development: language history as a moderating variable.

Purpose: The present study examined the nature of concurrent and predictive associations between conversational language use and reading development during early school-age years.

Method: Language and reading data from 380 twins in the Western Reserve Reading Project were examined via phenotypic correlations and multilevel modeling on exploratory latent factors.

Results: In the concurrent prediction of children's early reading abilities, a significant interaction emerged between children's conversational language abilities and their history of reported language difficulties.

Use of the Twin Design to Examine Evocative Gene-Environment Effects within a Conversational Context.

The purpose of this study was to highlight the role of twin designs in understanding children's conversational interactions. Specifically, we (a) attempted to replicate the findings of genetic effects on children's conversational language use reported in DeThorne et al. (2008), and (b) examined whether the language used by examiners in their conversation with twins reflected differences in the children's genetic similarity.

Children's history of speech-language difficulties: genetic influences and associations with reading-related measures.

Purpose: This study examined (a) the extent of genetic and environmental influences on children's articulation and language difficulties and (b) the phenotypic associations between such difficulties and direct assessments of reading-related skills during early school-age years.

Method: Behavioral genetic analyses focused on parent-report data regarding the speech-language skills of 248 twin pairs (M = 6.08 years) from the Western Reserve Reading Project.

Listeners' Perceptions of Language Use in Children.

Past research suggests that when children's communication skills do not match others' expectations, children are likely to be perceived negatively and may consequently experience less academic and social success. This project focused on listeners' perceptions of three children, one with specific language impairment (SLI) and two typically developing peers. The listeners consisted of teachers, speech-language pathologists, undergraduate students, and sixth-grade students.