This study investigated developmental changes in choices of action, particularly with regard to participants' leg length. Each of 128 children and 18 adult participants was asked to walk beyond a rope by either stepping over it or passing under it. The rope height was changed up and down from a point half of each participant's height. The highest rope height over which a participant stepped was called one's 'transition point.' Additionally, we called the highest stepping-over rope for which individuals did not touch the rope the 'success point.' Dividing each of these heights by the person's leg length, we calculated a 'transition ratio' and a 'success ratio.' The transition ratio and success ratio value became almost equal after age 7. The transition ratio value of males was higher than that of females. It follows from these results that stepping-over or passing-under was chosen based on the relation between leg length and the rope height. Humans apparently gain such a perception at age 6 or 7. The discussion also considered that 4-6-year old children can perceive their leg length and physical ability, and that the lower transition ratio of females is related to their avoidance of the risk of falling down.

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This research investigated the gaze effect among 3- to 5-year olds. The gaze effect is observed among young children including newborn babies, when using the direction of gaze by the participants themselves as a measurement marker. The study attempted to use an action as the marker by employing a cueing paradigm. The gaze effect was observed among 5-year olds but not among 3-year olds. This result demonstrates that a transition occurs from a state without a gaze effect to a state with it, between 3 and 5 years of age. A computational model was constructed on the assumption that the causes of this transition were (1) an increasing shift of attention with age and (2) a rapid developmental expansion in the scope of attention occurring around age of four. The model was simulated on a computer that produced data similar to that of the experiment, appearing to confirm the validity of the assumed computational model.

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This study verified that knowledge is reconstructed through awareness (noticing the different ideas of other people) and self-reflection (comparing and examining these differences), and that such knowledge is stable. Third graders performed a pre-test, collaborative session, post-test, and delay-test sequence of tasks. On all the tests, we presented different situations to clarify whether knowledge improvement was due to reconstructed knowledge or to refined preexisting knowledge. In the collaborative session, 2 factors (awareness and self-reflection) were manipulated, resulting in 4 conditions. The results showed that the degree of knowledge improvement was stable even in the situation which required reconstructed knowledge, and that only in the condition whereby the other person's different ideas were presented and there was self-reflection.

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An experiment was conducted on 68 children, ages 4-6 years, to clarify the specific relations between their numerical abilities and finger dexterity. Multiple regression analysis showed that performances by participants on arithmetic tests were strongly influenced by their performances in finger dexterity. In addition, their performance on vocabulary tests was most strongly influenced by their abilities in rhythmic movement. These findings suggest that numerical abilities in 4-6 years old is more strongly related to finger dexterity than to other movement skill, and that finger dexterity is more related to numerical abilities than verbal ability. The results are discussed in terms of the localizationist and the functional hypotheses.

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Infants start to actively point at objects of interest from around their first birthday. This behavior, called "declarative pointing," has been thought to function to redirect others' attention towards an object to express interest in sharing that object with others. However, it remains unknown whether infants' use of declarative pointing is actually based on the understanding that they can share experiences with others. We investigated whether 1-year olds (younger group n=34; older group n=28) changed their pointing behavior according to others' attentional status, and whether they chose target objects based on experiences previously shared with others. The results showed that the older infants stopped pointing soon after the experimenter paid attention to the target object. Moreover, infants who had stopped pointing following the experimenter's attentional shift chose the target object more frequently than they chose other objects. Such choices are construed as based on an understanding of experiences previously shared with the experimenter. The discussion focuses on the developmental relations between declarative pointing and infants' understanding of shared experience.

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This paper examined two longitudinal studies, the first of which analyzed responses of 68 participants on an independent and interdependent self-construal scale (Takata et al., 1996) from late childhood through adolescence. The second longitudinal study included 152 participants between late adolescence and young adulthood. These investigations indicated that interdependence decreased between late childhood and early adolescence, increased from early adolescence to middle/late adolescence, and again decreased between late adolescence and young adulthood. Such developmental trends were consistent with those of shown in a cross-sectional study (Takata, 1999), and Structural Equation Model analysis revealed that one's level of interdependence at one developmental stage had positive effects on that during the next stage. Longitudinal independent scores, however, changed neither between late childhood and late adolescence, nor between late adolescence and young adulthood. This was in contrast with the results of a cross-sectional study that revealed a decrease from late childhood to early adolescent, and an increase between late adolescence and young adulthood. In sum, these findings suggest that in Japanese culture interdependent self-construal is actively internalized through the adolescents' reconstruction of self.

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This study examined Virtual Acid Responses ("VAR") as representatives of the mechanism of identification in infancy. VAR is a very ordinary phenomenon which occurs in perception of another person's eating something sour. Individuals who tasted a pickled plum express sourness facially when seeing a person eating a plum with a neutral facial expression. In this case, a baby would experience VAR as if she had eaten the pickled plum herself. Forty-three infants (younger group ages 5-9 months, n=22; older-group ages 9-14 months, n=21) participated in this study. Infants in the experimental group (Lemontasting group, or "LE") tasted a lemon and then were presented with a situation where the experimenter tasted a lemon while making a neutral facial expression. Control group infants (Non-lemon-tasting group, or NLE) did not taste the lemon but instead ate a small piece of soft-rice-cracker, and were then presented the same stimulus as the experimental group infants. The reactions of infants were coded into nine behavioral categories. The key findings were that (1) LE babies showed significantly more numbers of categories compared to NLE babies; (2) LE babies in the younger group tended to show frowning and lip-movements, although LE babies in the older group tended to show reaching and vocalizing; and (3) reactions related to VAR in the LE group were equal or more obvious compared to those of NLE babies presented with aversive facial expressions by adult model.

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This study investigated correlations between understanding of mental states and the social interactions of 5- and 6-year old children. Participants (N=102, 46 boys and 56 girls) took false belief tasks and hidden emotion tasks to assess their understanding of mental states. Teachers rated children's social interactions in terms of sympathetic behavior and peer relationships. The results indicated that, controlling for age, gender, and vocabulary scores, understanding of false beliefs was significantly associated with sympathetic behavior and peer acceptance. In addition, children with both low ability to understand false beliefs and high ability to understand hidden emotions rarely showed sympathetic behavior, and they were likely to have difficulty in forming high quality peer relationships. These findings are discussed in terms of the integration of understanding false beliefs and hidden emotions as a factor contributing to the development of social interactions.

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Items for a parental child rearing scale were developed by several clinical psychologists and pediatricians who had experience with parent training and had worked with parents of children with developmental disabilities. A questionnaire survey was taken by more than 7,000 parents and caregivers of preschool, elementary school, and middle school children. Factor analysis of their data revealed a 5-factor solution: positive rearing, consultation/care, scolding, difficulty in upbringing up, and difficulty in care. Positive rearing and consultation/care were negatively related to ADHD tendencies, whereas scolding, difficulty in bringing up, and difficulty in care were positively related to ADHD tendencies. In addition, subscales of parental child rearing style, except for positive rearing, changed non-linearly as the children's age increased. The discussion focused on the use of the Parental Child Rearing Scale.

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This study examined 5 contexts (home, leisure time, workplace, lessons, and friendship) in terms of their importance for the identities of 152 single working women. The results showed a big difference in the importance of "home" rather than "workplace" between women who work continuously and those who leave work. This result suggests that the declining number of women who see "home" as important is related to the contemporary increase in working women. Interestingly, although contexts seen as important differed for each individual, there were no differences in their identity scores in such contexts. Finally, it seems that context-specific factors including identity in the context of "home" and "workplace" relate to life course differences. In future research, an examination is needed of the complex relationships between factors such as context-specific identities, their influences on identity formation, and life course differences.

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