Turkish-speaking dyzygotic twins (n = 21) and singletons (n = 23) were tested through a standard articulation test to observe whether their consonant articulations were related to their vocabulary sizes, recorded through CDI forms, at age 3;0. Twins were observed to lag behind their singleton peers and performed below the norm level in their…

Children's early vocabulary shows sex differences -- with boys having smaller vocabularies than age-comparable girls -- a pattern that becomes evident in both singletons and twins. Twins also use fewer words than their singleton peers. However, we know relatively less about sex differences in early gesturing in singletons or twins, and also how…

Our aim was to assess whether infants influence the quantity and quality of their mothers' speech to them and, in turn, whether this maternal speech influences children's later language. As 189 mothers interacted with each of their twins at age 0;5, we calculated the number of utterances, the proportion of sensitive utterances, and the proportion…

Assessed the language development of 2,898 pairs of 2-year-old twins born in England and Wales using the MacArthur Communicative language Development Inventory, which assesses vocabulary and grammar. Moderate heritabilities were found for both. (Author/VWL)

Multivariate genetic analysis was used to examine the genetic and environmental aetiology of the interrelationships of diverse linguistic skills. This study used data from a large sample of 4 1/2-year-old twins who were tested on measures assessing articulation, phonology, grammar, vocabulary, and verbal memory. Phenotypic analysis suggested two…

Analysis of speech samples from four-year-old monozygotic and dizygotic twins revealed that the monozygotic twins were significantly more likely to misproduce the same sound on an articulation test than were dizygotic twins. The dizygotic twins were no more likely to share errors than were children who were both genetically and environmentally…

Crib-talk between identical twin girls and diary records of their speech were examined. It was found that the subjects developed conventional syntax and vocabulary but adapted them in ways which appropriately expressed their twin status. (Author/SED)

Examines conversational interaction in mother-twin-twin triads during play. Findings, paralleling those for mother-infant-sibling triads, reveal that these conversations are five times longer and elicit more turns from all speakers than dyadic conversations between a mother and a single twin and that the unique effects of triadic exchanges are not…

The claim that multiple-birth children use "twin language" was investigated by describing and comparing the phonological characteristics of the speech of 19 sets of multiple birth children (aged 2-4) and by measuring multiple-birth children's understanding of their twins' or triplets' context-free speech. Results indicated that multiple…

A blind child and her sighted twin sister were recorded at home once a month from 2;5 to 3;5, and their repetitions and routines were analyzed with respect to three dimensions. Results showed that the blind twin used routines and modified imitations and repetitions more frequently, and her use of modified repetitions increased during the study.…

We investigated infant precursors of low language scores in early childhood. The sample included 373 probands in 130 monozygotic (MZ) and 109 same-sex dizygotic (DZ) twin pairs in which at least one member of the pair scored in the lowest 15th percentile of a control sample on a general language factor derived from tester-administered tests at…

Gaze during utterance was examined in a set of bilingual-bimodal twins acquiring spoken English and American Sign Language (ASL) and a set of monolingual twins acquiring ASL. The bilingual-bimodal twins differentiated their languages by age 3. Like the monolingual twins, the bilingual-bimodal twins established mutual gaze at the beginning of their…

A set of tri-zygotic quadruplets, three girls and one boy, participated in weekly observations from 1;2 to 1;10 (years;months), a period of transition from prelinguistic gesture to 50 words. In the study, one girl served as a genetic mate to her identical twin and a biological risk mate to her fraternal sister. The biological risk mates achieved…