言語行動の発達(III) : 母子相互作用と象徴遊び : 2から23か月児の擬似縦断資料の分析

The nature of mother-infant interaction in play situation was explored in a quasi-longitudinal study of 20 mother-infant dyads. Eight infants for months 2-5, four infants for months 6-11, four infants for months 12-17 and four infants for months 18-23 and their mothers were observed once a fortnight at their home. Data of 149 semi-structured play sessions with a variety of toys were analyzed. In the present paper, the analysis focused not only on the functions (initiative or responsive) and types of behaviour (gestural or vocal) but also on the levels of infant's and mother's play, of which the symbolic play level was the highest. A comparison between infant's play level and mother's play level at every two months of age revealed that the development of infant's play interacted with mother's play behaviour. During the first several months of our observation period, while infant's play was classified only to lower levels, mother's play was quite often classified into higher levels including symbolic play level. However, as infant's play behaviour progressed, mother's play levels became more correspondent to infant's play levels. As for symbolic play of infant, it was observed after 8 or 9 months of age in gestural and vocal mode, but it was only after 20 months of age that symbolic play became frequent and accompanied also frequently language expressions. It was suggested that the nature of mother-infant interaction in play changed around 20 months of age and that this was essentially due to the development of infant language with symbolic play