Sex differences in attachment are absent during infancy and early childhood, emerge in middle childhood with self-reports and doll-play tasks, and persist into adulthood, when they are most reliably detected in romantic attachment styles. In our previous work, we hypothesized that sex differences in attachment develop under the influence of adrenal androgens during the transition form early to middle childhood, following activation of hormone-sensitive neural pathways organized by prenatal and early postnatal exposure to sex hormones. In this study we tested the association between the right-hand 2D:4D digit ratio (a marker of early exposure to androgens and estrogen) and sexually differentiated dimensions of attachment in middle childhood assessed with the Coping Strategies Questionnaire (CSQ). In a sample of 285 Italian children aged 8-10 years, females scored lower in avoidance and higher in preoccupation, while no significant sex differences were observed in felt security. Consistent with our predictions, higher (feminized) digit ratios were significantly associated with lower avoidance and higher preoccupation scores in both males and females. In contrast, there was no significant association between digit ratio and felt security in either sex. These results corroborate the hypothesis that sex differences in attachment reflect the activation of sexually differentiated pathways organized in early development, and for the first time implicate sex hormones in the development of individual differences in attachment styles.

Objective: The purpose of this study was to examine the bidirectional relation between mobile phone dependency (MPD) and self-regulated learning (SRL) of early Korean adolescents in 4 th , 6 th and 8 th grade, while taking into account gender differences. Methods: The study made use of panel data from the Korean Children and Youth Panel Study (KCYPS), and three waves of data collected from 2,264 adolescents were analyzed by means of autoregressive cross-lagged modeling. Results: The results can be summarized as follows. Firstly, MPD and SRL were consistently stable for adolescents in 4 th , 6 th to 8 th grades. Secondly, a bidirectional relations between MPD and SRL were confirmed. In other words, there was a significant influence of a high level of MPD on a subsequent low level of SRL, and the high level of SRL also had a significant effect on the lower level of MPD across time. According to multi-group analysis, no gender differences were found in the relations between two constructs during the studied period. Conclusion: Findings highlighted not only the necessary media usage education but also parenting intervention strategies may help early adolescents to be prevented from negative effects of media usage and to enhance self-regulated learning ability. Based on the results, more implications were also discussed.

In upper elementary period school adjustment and the effect of parenting face a new set of dynamics. We assumed that parental supervision, affection, incoherence, over-expectation, over-interruption and logical explanation would have an effect on individual trajectories in the development of school adjustment. Additionally, we hypothesized that this model would be different among boys and girls. In this study we analyzed three waves of data collected from 2,378 children nationwide in South Korea. This data was gathered from the Panel Study of Korean Youth and Adolescents conducted by the National Youth Policy Institute(NYPI). Growth-curve longitudinal analysis was conducted and the results indicate that levels of school adjustment had decreased through the 4 th to 6 th grade. Parents' supervision, affection and logical explanation significantly predict children's initial school adjustment as well as their rate of decrease in their levels of school adjustment. Parents'

This study aimed to investigate the cognition of life phenomenon regarding anthropomorphic characters according to the characters' properties amongst children aged 3, 4, and 5. Methods: 95 children aged 3 to 5 years from two childcare centers located in Seoul and Gyeonggido participated in this study. Each child was interviewed individually and completed cognition and inference of life phenomenon tasks. Results: First, preschoolers considered anthropomorphic animal characters as animals. Children aged 3, 4, and 5 were likely to refer to the animation characters as alive and considered animation characters to have many biological and psychological traits. Second, there were significant differences in children's inferences of life phenomena according to the properties of the anthropomorphic characters. Preschoolers considered low anthropomorphic animation characters to have more biological traits and reality. For low actuality characters, preschoolers considered them to have more reality. Third, there were significant differences in children's inferences of reality according to their age: 5-year-olds were more likely to infer the animation character as an imaginary entity, compared to 3-year-olds. Conclusion: As the literature related to children's cognition about anthropomorphic characters is limited, this study investigated what children think about animation characters and offers useful guidelines for the development of educational media or applications for young children.

Objective: The purpose of this study was to examine the changes of childcare expenses and private education expenses caused by target expanding the childcare subsidy policy and its relationship to household income. Methods: The study analyzed data of the Korean Welfare Panel Study from 2009, before the universal childcare policy was enforced, to 2013, when the universal childcare policy was enforced. Results and Conclusion: The results of analysis were as follows. First, while childcare expenses, private education expenses, and their ratios to household income showed a tendency of gradual decline, the graphs of childcare and private education expenses were symmetric. Second, there were differences in childcare and private education expenses among income classes. Third, in 2009, before the universal childcare policy was enforced, household income affected childcare and private expenses. Lastly, in 2013, after the universal childcare policy was implemented, household income had a greater effect on private education expenses, while the effect of household income on childcare expenses became insignificant.