This article discusses sociohistorical properties of children at play and childhood development. The following three main points are discussed. 1. Awareness of the researcher's own intentions and participation in social practice are both essential for the study of children at play. All young children should enjoy play every day, but in our society children do not play enough. I participate in social practices to enrich their lives with play. 2. I give meaning to the facts I encounter through that practice. As each child's play is a once-off event, study methodology cannot be the same as in the natural sciences. So it is important to have a historical perspective as researchers. 3. The same methodology as found in developmental psychology may be applied. The actual development of a child is not normative, but is a once-off story when viewed historically. Because each child is unique, no two childhoods are the same developmentally. Therefore, an approach emphasizing uniqueness of individual development is necessary.

This study took place at Tarama Island (Okinawa, Japan) and examined changes in two types of allomothering (non-maternal childrearing system): traditional babysitting and institutionalized childcare in day nurseries. Framed within a social dynamics approach, this work proposed a human developmental perspective comprised by “era” and “locality.” We first investigated the transition of moriane (Okinawa's unique approach to babysitting) across different eras. Women born between 1943 and 1952 had the highest rate of moriane experiences, and this became less common thereafter although it has increased slightly in recent years. The establishment of a day nursery in 1979 was associated with mothers' higher educational expectations at that time. In addition, changes in childrearing practices were related to the development of social and educational infrastructure, and population dynamics. Around 1950, when the practice of moriane was the most prevalent, children under 15 years of age outnumbered adults (10% of the population was comprised by children under 3 years of age). Thereafter, adults have outnumbered children. Utilities such as electricity and water supply became available around 1972, with the return of Okinawa to Japan. In conclusion, based on the implications of allomothering practices on Tarama Island, we may debate the premises or biases related to understanding children from the perspective of developmental psychology.

This article critiques the theories of Theory of Mind (ToM), and proposes an alternative phenomenological framework that demarcates a socio-cultural construction process and its resulting social understanding. First, we observe that the ToM framework and its cognitive science background originated from the premise that a representational understanding of an unobservable mind (i.e., mind-reading) is an intrinsic, universal ability from a third-person perspective. The author then reviews recent phenomenological explanations and their multi- or dual-process models of social cognition which includes implicit false-belief understanding, that emphasize first- and second-person perspectives of social interaction. It is argued that although it may be the most plausible framework of social understanding, the phenomenological model still lacks enough consideration of socio-cultural construction, a process which should be universal across socio-historical contexts. We further assert that ToM, believed to be the one and only universal cognitive process, is nothing more than an outcome of such socio-cultural processes.

Self-esteem is one of the popular constructs in psychological studies, and there have been many studies wherein a meta-analysis of self-esteem research has been conducted. This study focused on research involving cross-temporal meta-analyses, wherein samples who completed the same psychological questionnaires at different points in historical time are located. Oshio et al. (2014) found that mean scores of self-esteem tended to decrease with survey year. Okada et al. (2015) conducted a meta-analysis to examine gender differences in reported self-esteem in Japan, and found that effect size decreased with survey year. This article provides a detailed description of cross-temporal research on self-esteem and discusses the direction of future research on self-esteem from the perspective of historical change.

This paper adopts two central viewpoints in consideration of reasonable accommodation for children with disabilities. First, children should be recognized with regard to not only their individuality but also various situational inter-relationships. To describe ambiguity in the understanding of their own latent world, discussions of methodological considerations were formulated. Secondly, the International Classification of Functioning, Disability and Health (ICF) framework, which integrates the major models of disability, was taken as a basis for discussion. It is argued that real reasonable accommodation can be made only when the role of environmental factors in creating the disability is recognized, as in the ICF framework. These viewpoints suggest that human development should be interpreted in consideration of its historical meaning, concreteness of the regional space context, and the unique and special existence of individuals.

The epidemiological and historical sociology of autism spectrum disorder (ASD) suggests that the concept of ‘social communication and interaction' included in its diagnostic criteria may lead people to mistake ‘inter-personal phenomena' that alternate continuously based on time and place, for persistent ‘intra-personal phenomena.' Because persistent characteristics that exist independent of social relationships may be diverse among ASD, it is necessary to extract them in a case-by-case manner. Accordingly, we have been doing tojisha-kenkyu (person-centered research) for 8 years with Ayaya, who is a researcher diagnosed with ASD. The results revealed the following possibilities: 1) atypical regulation under interoception-driven long-term goals causes difficulties in motor control, selective retrieval and systematic consolidation of memories; and 2) enhanced interoception fails to be integrated with exteroceptions, which causes difficulties in constructing the emotions and intrinsic intentions of one's self and others, and hyper- and hyposensitivity to sensory inputs and prediction errors. Tojisha-kenkyu has not only academic significance, but it may also lead to therapeutic effects on well-being by making it possible to grasp trans-situational invariants of the self.

This article provides suggestions and questions to Japanese developmental psychological studies from a youth transition researcher. Over the last few decades, young people's transition to adulthood has been lengthened in Japan and other Western countries, with regard to stable employment, leaving home and marriage. In accord with this change, adolescence/youth researchers in America and Europe are introducing and debating new theories, such as Arnett's theory of emerging adulthood, to explain this prolonged transition. The most critical point under debate is whether or not emerging adulthood is a new universal developmental stage for youth in industrialized countries. Arnett claims universality, but other researchers argue that emerging adulthood applies only to middle class youth who can afford to attend universities, while ignoring the experiences of disadvantaged youth. In Japan, although there have been many developmental psychological studies of adolescence, there seem to be few that focus on the prolongation of the transition. It may be a serious point that most psychological research on adolescents focus only on those who will obtain higher education, while less educated youth seem to be invisible to psychologists in Japan.

The present study explored the characteristics of friendship in contemporary adolescence. The first part of the study compared surveys conducted between 1989 and 2010 on friendship item scores. The results showed that friendship characteristics had not changed much over the years. The second part of the study explored how two characteristics of friendship, self-consciousness and narcissism, were related to “commu-phobic” tendencies and the “lunch-mate syndrome.” This study further examined individual differences among contemporary adolescents. The analysis showed that “lunch-mate syndrome” tendencies correlated with hypervigilant narcissism. It was suggested that participants with strong “lunch-mate syndrome” tendencies remained in a state of high anxiety concerning what their friends thought about them, whereas participants with “commu-phobic” tendencies avoided close relationships with their friends, to escape their anxieties. To find an effective explanation for contemporary adolescent behavior, it is important for developmental psychologists to pay attention not only to the overall picture but also to individual differences among adolescents, and to causal mechanisms of the phenomenon.

This paper described interfaces between a child's language learning and the age of globalization, and focused on daily practices that foster biliteracy of children in German-Japanese families. Our previous studies and some new data were presented for discussion. Two characteristics of family practices for the development of children's Japanese literacy emerged. First, parental support for their children was continuously carried out with the use of available resources, as defined by the German school system and their social-linguistic environment. Second, families collaborated to overcome critical problems that occurred not only for their children with age, but also due to friction between the family, and local and supplementary schools. These findings have three implications for language developmental study, showing the necessity to (1) consider the extension and diversity of children who learn Japanese, (2) examine children's language developmental processes from long-term and holistic perspectives, not restricted to language skill acquisition, and (3) view a child's literacy development as a collaborative practice with his/her family members, embedded in their daily lives.

In light of recent updates which imply delays in Japanese toddlers' self-development, this study investigated changes over the years in the compliance and non-compliance of 2 year-olds as an indicator of self-development in early childhood. We observed and examined the behaviors of 2-year-olds (N＝111) in 2004 and 2005 (Wave 1) and 2-year-olds (N＝95) in 2010 and 2011 (Wave 2), during a toy-cleanup procedure. Compared with the children in Wave 1, fewer children in Wave 2 showed a refusal reaction to the requests from strangers to clean up the toys they played with. In addition, children in Wave 2 showed more compliant reactions and less defiance or refusal toward their mothers during mother-child cleanup situations. These findings suggest that toddlers today may be experiencing delays in recognition of the difference between their and others' intentions and in expressing their will. Implications of the data are discussed, regarding changes in children's behaviors and maternal reactions with regard to self-development, or rapid changes in the parent-child environment, which may account for changes over the years in children's compliance or non-compliance.

This study explored the development of adolescent health-related physical fitness and the secular trend of its trajectory. Data for the study were drawn from archival data of the secondary school attending the University of Tokyo's Faculty of Education. Participants for endurance running were 3,763 adolescents (1,870 females) who entered the school between 1968 and 2001, and those for grip strength were 2,137 adolescents (1,072 females) who entered the school between 1968 and 1987. The results of latent growth curve modeling showed that males improved in their endurance running performance and grip strength during adolescence. Meanwhile, females did not greatly change their endurance running performance and slightly improved in their grip strength during adolescence. In addition, the results also indicated a secular trend in their developmental trajectories. Later-born cohorts showed a decline of endurance running performance for both sexes. Meanwhile, these cohorts also showed an increase in grip strength, but only for male adolescents.

Social support is one of the factors that promotes mental health among adolescents. The current cross-sectional study of 4th–9th grade students investigated the effects of social support on mental health problems such as depression and aggression. Using general linear model and controlling for gender, age, and stressors, it was found that students who perceived more social support from peer and/or adults exhibited lower levels of depression. In addition, gender was related to associations between social support and depression – girls showed stronger associations than boys. A negative but weak effect of peer support on aggression was also notable, although we did not find the same effects for adult support on aggression. According to an analysis of relationships between gender/age and levels of social support, girls perceived more social support from peers and adults than boys. Finally, students in higher grade levels perceived more peer support and less adult support.

Along with an increase in the number of Japanese people suffering economic hardship, the problems of children in poverty have been especially exacerbated. Economic factors have an effect on not only the necessities of life for these children, but also their social relations. The purpose of the study was to examine the characteristics of social support in children from impoverished households. Junior high school students from households on welfare (n＝132) and students from ordinary households (n＝256) completed the SESS measuring social support, and the KINDL, a measure of quality of life (QOL). The results showed that students from impoverished households perceived support from their teachers as lacking, compared to students from ordinary households. Among students from ordinary households, support from parents, teachers, and friends were associated with QOL scores. Among students from impoverished households, support from friends was associated with QOL scores, but support from their teachers was not associated with any QOL scores. These results suggest that more support in school is required for children from impoverished households.

The purpose of this research was to consider the influence of expressions of kindness from others on children's subsequent development of social information processing (SIP) styles during ambiguous provocative situations. A total of 247 children from grades 4–6 of elementary school completed a questionnaire based on the SIP model, and structural equation modeling was used to verify causality of each variable. For both children who had reported receiving expressions of kindness from others and those that had not, hostile attributions were inversely related to friendly goal setting, and friendly goal setting was inversely related to aggressive behaviors, suggesting a positive relationship to behaviors demonstrating anger restraint. An ANOVA was conducted to verify the influence of others' expressions of kindness, age, and sex on SIP. The results suggested that negative SIP styles in children increased significantly with age, and negative SIP styles were possibly moderated by expressions of kindness from others.