Origins of a theory of mind.

Twenty-two pairs of typically developing toddlers (M=24.32 months) and their mothers were observed in a play-room solving puzzles during 30 min. The target of the observations was hand-taking gesture.

Gaze following among toddlers.

Children's cooperative activities with their peers become markedly coordinated during the 3rd year of life. During these activities, the child needs to follow his/her peers' gaze to objects, and look at the same objects to initiate coordinated action. Since 3-year-olds' ability to follow their peers' gaze has not been studied, we experimentally investigated this in our study.

Do pointing gestures by infants provoke comments from adults?

In the field of developmental psychology, there is speculation that pointing gestures by infants are good precursors of infant language acquisition, and some researchers have found correlations between these pointing gestures and some indices of language acquisition. Infants' pointing gestures are presumably related to language acquisition because they provoke verbal responses from adults. To test this, seven boys and six girls were observed during free play time in a nursery classroom, and post-pointing and matched-control data were collected.

Development of eating behavior by Japanese toddlers in a nursery school: relation to independent walking.

The eating behavior of 32 toddlers in a nursery school at 10, 12, and 14 months old was observed in relation to the age at onset of independent walking. With increasing age, the frequency at which the toddlers ate food given by a teacher decreased, and the frequency at which the toddlers ate by themselves increased. The toddlers who started walking earlier also advanced faster in the development of eating behavior.

[Indoor and outdoor peer relations in preschool children].

This study examined whether the choice of interactors is influenced by indoor and outdoor situations. Peer relations among twenty three-year-old, eighteen four-year-old, and twenty five-year-old children in an urban preschool in Japan were observed during indoor and outdoor free play situations. We analyzed the partners in the interactions, the number, and the stability of interactors.

Grooming relationships of adolescent orphans in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama: a comparison among orphans with sisters, orphans without sisters, and females with a surviving mother.

The present study examined grooming relationships of adolescent females in a free-ranging group of Japanese macaques (Macaca fuscata) at Katsuyama. To assess whether the loss of the mother influenced the grooming relationships of adolescent females (5-7 years old), we compared the time spent in grooming interactions and the number of grooming partners among the following three groups: 6 adolescent orphans with sisters, 9 adolescent orphans without sisters, and 11 adolescent non-orphans with surviving mothers. In Japanese macaques, grooming most frequently occurs between mothers and their daughters.