Sibling language: Conversational interactions in dyadic and triadic family groupings

The purpose of the study was to describe sibling language directed towards mothers and younger children when family members were in dyadic and triadic groupings. Barton and Tomasello (1991) suggested that siblings provide a challenging language environment for younger brothers and sisters which influences later peer interactions. In this study, the emphasis was placed upon the capabilities of older siblings as they modified child-directed language in sibling-child pairs as well as in more complex mother-sibling-child triads. Six family groups consisting of mother, sibling and child participated. Older siblings ranged from 5:1 years to 8:6 years and younger children ranged from 2:8 years to 4:0 years of age. Each family group was recorded in a playroom setting four times. The initial interaction was the mother-sibling-child triad followed by mother-child, mother-sibling and sibling-child dyads. Language was recorded, transcribed and coded using CHAT conventions and was analyzed using the CLAN system. Paired sample t-tests were used to compare MLU, type-token ratio, and proportional use of conversational acts across dyadic and triadic settings. Qualitative analyses of semantic category usage were conducted on language transcripts from three specific families. As predicted, it was found that siblings made conversational adjustments in their child-directed speech by shortening utterances, but that these adjustments were lessened by the demands of the triadic setting. Neither siblings nor mothers showed simplification of lexical diversity as measured by type-token ratio in any setting. Siblings showed evidence of specific patterns of conversational act use in child-directed speech including higher use of performatives, descriptions of events, identifications and requests for actions as compared to mothers in their child-directed speech. Mothers used more yes-no and wh-questions and more repetitions than siblings when comparing their child-directed speech. Patterns of semantic category use emerged from qualitative analyses and indicated that mothers consistently used Action and Object categories in child-directed speech across settings, while siblings used only Action consistently. The qualitative descriptions will enable future research to be guided by the similarities and differences that were identified