18ヵ月から始まるふり遊びは，子どもの社会性の発達にとって重要なものである。しかしこれまで，ふり遊びがどのように発達するかについては明らかにされてこなかった。本研究では，乳幼児期のふり遊びの発達について，18ヵ月，24ヵ月，30ヵ月の子どもの母親との遊びの観察から検討を行った。その結果，18ヵ月児，24ヵ月児にとっては母親の働きかけが必要であるが，30ヵ月児になると，母親の働きかけなしに子どもが主体的にふり遊び出来るようになることが示された。 / Pretend play, or make-believe play, is important for child development. However, the development of mother-child pretend play in the toddler years has not been clear. Through this study, we aimed to examine the development of mother-child pretend play in the toddler years. Participants were 18-, 24-, and 30-month-olds and their mothers. We observed these 3 groups in a mother-child pretend-play session. Results indicated that 18- and 24-month-olds need their mothers to exhibit pretense signals. However, 30-month-olds do not need this. In sum, pretend play in the toddler years develops from the stage where the mother's pretense signals are necessary to that where the child becomes independent. / 博士(心理学) / Doctor of Philosophy in Psychology / 同志社大学 / Doshisha University