Ik post het maar even hier omdat de mensen waarmee ik het erover had nu vooral hier zitten, geloof ik. Een tijdje geleden kwam ter sprake dat over het algemeen de taalontwikkeling bij jongere broertjes en zusjes langzamer gaat. We speculeerden er toen over hoe dat kon en of er niet ook voordelen zouden zitten aan het hebben van een oudere broer of zus.
Afgelopen week kwam ik ineens een artikel tegen waarin dit soort onderzoek aan bod komt! Het gaat niet om één onderzoek, maar om een reviewartikel waarin de uitkomsten van meerdere onderzoeken besproken worden: "How social contexts support and shape language development" van Erika Hoff. Wie geïnteresseerd is in het hele stuk moet me maar even pm'en (er wordt bijvoorbeeld ook iets gezegd over de invloed van kinderdagverblijven op de taalonwikkeling). De relevante passage:
Birth order influences on language environments and language development
In cultures and in families in which children are cared for in the home by their mothers, the first born child experiences a different early social and language environment than do later born children. First born children are temporarily only children, and while that status lasts they have greater possibilities for communicative interaction with an adult and greater exposure to adults’ child-directed speech than later borns ever do. When a sibling is present, each child receives less speech directed solely at him or her because mothers produce the same amount of speech whether interacting with one or two children (Jones & Adamson, 1987). In addition, the functions of mothers’ speech differ depending on whether they are interacting with one or two children. Mothers’ speech in triadic interactions is more centered around activities and social interaction whereas speech in dyadic interaction contains more talk about language itself (Oshima-Takane & Robbins, 2003). There also may be structural and lexical differences in the speech mothers address to first and later born children, but the evidence here is scanty and does not yield a consistent account of such differences (Hoff-Ginsberg, 1998). The role of older siblings as a source of input is another reason that the language environments of first and later born children differ (Hart & Risley, 1999). Older siblings differ from mothers in the speech they address to young children: their speech more frequently serves social-regulatory functions (Oshima-Takane & Robbins, 2003), is structurally less complex, and uses a smaller vocabulary (Hoff-Ginsberg & Krueger, 1991).
With respect to birth order effects on language outcomes, first borns appear to have an early advantage in the development of vocabulary and syntax, but later borns may have an advantage in the development of conversational skills. Later borns also have been found to be more advanced in the production of personal pronouns than first born children (Oshima-Takane, Goodz, & Deverensky, 1996). Evidence of a general first born advantage in early vocabulary development comes from several studies. Fenson et al. (1994) found significant birth order-related differences in children between 8 and 30 months using the MCDI, although birth order accounted for only 1% of the variance. In 20-month-old children, Jones and Adamson (1987) also found birth order-related differences using maternal report, but no differences appeared in spontaneous speech. In 24-month-olds, Hoff-Ginsberg (1998) found first borns used larger vocabularies in spontaneous speech, and first borns have been found to reach the 50-word milestone on average one month sooner than their second born siblings (Pine, 1995). The early path of vocabulary development may also be affected by birth order. First borns are particularly likely to show a referential style of vocabulary acquisition, such that their vocabularies are more dominated by object labels than the vocabularies of later borns, who are more likely to be expressive-style language learners (Goldfield & Reznick, 1990). Evidence is equivocal with respect to longer term vocabulary differences associated with birth order. Hart and Risley (1999) found no differences at age 3 years, but a literature review found first borns and only children scored higher on standardized tests of vocabulary (Bates, 1975).
Evidence of a first born advantage with respect to syntactic development comes from studies of spontaneous speech and maternal reports during the preschool years (Bernicot & Roux, 1998; Fenson et al., 1994; Hoff-Ginsberg, 1998). There is also evidence that some language advantage for first borns persists through school age that may or may not have a syntactic basis. Again, Bates (1975) reported in a review of the literature to that date that most studies found first borns and only children scored higher on standardized tests of sentence comprehension, and other less well defined measures such as ‘‘enunciation’’ and ‘‘communicativeness’’ (e.g., Moore, 1968). Lieven (1994) and Pine (1995) also suggest that first born and later born children may take different routes in early syntactic development. They argue that first born children are more likely to take the analyze-first, speak-later route, whereas later born children are more likely to take the speak-first, analyze-later route characteristic of children in cultures where adults do not direct speech to prelinguistic children. Thus reliance on overheard speech and limited or no access to a captive conversational partner, whether due to culture or birth order, may give children less pre-parsed data to work with and at the same time push them to talk if they want to be included.
With respect to the development of communicative skill, there seem to be some advantages for later born children. Hoff-Ginsberg (1998) and Bernicot and Roux (1998) found later born preschool-aged children were less likely to produce noncontingent responses in conversation with their mothers than first born children of the same age. This could be because mothers become more supportive conversational partners with later born children, or it may be that the later born children have more pressure to learn the conversational skills required for entry into ongoing conversation (Dunn & Shatz, 1989). The advantage later borns show in communicative skill may also be a benefit of the opportunity for interaction with other children that siblings provide. Research on the role of peers in language development, which is discussed in a later section, suggests interactions with other children may make a unique contribution to children’s language learning experiences. These effects of birth order are consistent with the hypothesis that variation in access to communicative interaction and a language model produces variation in the rate of language development. The findings that first borns are more advanced in vocabulary and grammar but later borns are more advanced in conversational skill further suggest that different experiences are relevant to each aspect of development. They suggest that the development of conversational skill may be driven by motivational factors, but the acquisition of language per se is paced by the availability of data. The finding that later borns are more advanced in the production of personal pronouns is evidence that, even though overheard speech is not an adequate data base by itself, children do learn some things about language from the speech they overhear (Oshima-Takane et al., 1996).
I make it a thing, to glance in window panes and look pleased with myself.