A longitudinal study for the individual differences in phonetic discrimination in infancy and language development in childhood.

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K02636
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 09030:Childhood and nursery/pre-school education-related
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Yamane Naoto 国立研究開発法人理化学研究所, 脳神経科学研究センター, 専門職研究員 (60550192)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 乳幼児 / 言語発達 / 個人差 / 音韻弁別能力 / 縦断研究

Outline of Final Research Achievements

Measuring and understanding language skills at the early stage of life is important as it is the foundation for later language development. In the present study, we report results of a large scale study with Japanese infants that investigated whether infants’ family environment　impact infants’ vocabulary size at 20-month of age. The results revealed that　the vocabulary size of infants whose mother worked, or on maternal leave from their work was larger than infants whose mothers were no-worker. In contrast, household income, age and years of education of parents and interaction were not significant. These results suggested that Japanese infants’ vocabulary at 20 month is not impacted by SES, a sharp contrast to American infants. Current findings indicate that the predictor of infants’ vocabulary size by home environment at this age was not universal but culturally or linguistically different.

Free Research Field

発達心理学

Academic Significance and Societal Importance of the Research Achievements

本研究では発達早期の乳児の音韻弁別能力の個人差とその後の獲得語彙との相関関係、またそれらに与える家庭環境の検討を日本語学習環境にある親子を対象に大規模データから検討した。これらの結果から、乳児の音声知覚能力の個人差の存在とそれに与える家庭環境の影響を明らかにした。これまでに、乳児期の音韻弁別能力の個人差自体の検討に焦点を当てた研究は国内外を通し見当たらず、本研究で得られたデータは単に言語発達に関する研究としてだけではなく、子供の発達全般にかかわる貴重な研究資料となり得、教育・福祉分野などにおける貢献が見込まれる。