研究者詳細 - 山形　伸二

Returns to Education Using a Sample of Twins: Evidence from Japan 査読有り国際誌

Nakamuro Makiko, Inui Tomohiko, Yamagata Shinji

ASIAN ECONOMIC JOURNAL 31 巻 ( 1 ) 頁： 61 - 81 2017年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Asian Economic Journal

© 2017 East Asian Economic Association and John Wiley & Sons Australia, Ltd The objective of this article is to measure the causal effect of education on earnings using a large dataset of twins compiled in Japan with wide-ranging socioeconomic information. Recent research conducted in China showed that, contrary to the case in Western countries, ability bias is large in estimating the return to education. It is argued that the low rate of return in China is in part due to the competitive and exam-oriented education system, which is similar to the system in Japan. The empirical results in our study show that the estimated rate of return to education using the sample of identical twins in Japan is 9.3 percent even after omitted ability bias and measurement errors in self-reported schooling were corrected. Our findings suggest that the conventional OLS estimate is not significantly contaminated by potential biases in Japan.

DOI： 10.1111/asej.12113

Genetic and Environmental Influences on Traits of Gender Identity Disorder: A Study of Japanese Twins Across Developmental Stages 査読有り国際共著国際誌

Sasaki Shoko, Ozaki Koken, Yamagata Shinji, Takahashi Yusuke, Shikishima Chizuru, Kornacki Tamara, Nonaka Koichi, Ando Juko

ARCHIVES OF SEXUAL BEHAVIOR 45 巻 ( 7 ) 頁： 1681 - 1695 2016年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Archives of Sexual Behavior

© 2016, Springer Science+Business Media New York. The present study examined: (1) gender and age differences of mean gender identity disorder (GID) trait scores in Japanese twins; (2) the validity of the prenatal hormone transfer theory, which predicts that, in dizygotic (DZ) twin pairs, twins with an opposite-gender co-twin more frequently exhibit GID traits than twins with a same-gender co-twin; and (3) the magnitude of genetic and environmental influences on GID traits as a function of age and gender. Data from 1450 male twin pairs, 1882 female twin pairs, and 1022 DZ male–female pairs ranging from 3 to 26 years of age were analyzed. To quantify individual variances in GID traits, each participant completed four questionnaire items based on criteria for GID from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). Our most important findings were: (1) Japanese females exhibited GID traits more frequently than males and Japanese children exhibited GID traits less frequently than adolescents and adults (among females, the prevalence was 1.6 % in children, 10 % in adolescents, and 12 % in adults; among males, the prevalence was 0.5, 2, and 3 %, respectively); (2) the data did not support the prenatal hormone transfer theory for GID traits; and (3) a large part of the variance for GID traits in children was accounted for by familial factors; however, the magnitude was found to be greater in children than in adolescents or adults, particularly among females. This study suggests that although the prevalence is likely to increase, familial effects are likely to decrease as individuals age.

DOI： 10.1007/s10508-016-0821-4

多次元アクティブ・ラーナー尺度の作成と信頼性・妥当性の検討査読有り

山形伸二, 山田政寛, 中園晴貴, 田中岳, 新谷恭明, 丸野俊一

基幹教育紀要 = Bulletin of kikan education 2 巻頁： 86 - 94 2016年

記述言語：日本語掲載種別：研究論文（大学，研究機関等紀要）出版者・発行元：九州大学基幹教育院

This study developed Multi-Dimensional Active Learner Scale and examined its reliability and validity. Forty five items were developed in reference to the aims of KlKAN Education in Kyushu University. A questionnaire survey was completed by 353 undergraduate students. Results of exploratory factor analyses on the 45 items suggested six-factor solution, and 20 items were selected to achieve both ease of administration and reasonable reliability. The resultant scale consisted of six subscales: inquisitiveness, collaborative learning skills, striving to achievement, critical thinking, logical thinking, and perspective on university life. Confirmatory factor analysis on 20 items showed adequate fit. The overall scale and six subscales showed reasonable internal consistency (Cronbach's a = .86 for the overall scale, a = .62-.78 for the subscales). Correlations with self-directed learning, experience on group learning, and Big Five personality items suggested construct validity of the scale.

DOI： 10.15017/1650904

Genetic Factors of Individual Differences in Decision Making in Economic Behavior: A Japanese Twin Study using the Allais Problem 査読有り国際誌

Shikishima Chizuru, Hiraishi Kai, Yamagata Shinji, Ando Juko, Okada Mitsuhiro

FRONTIERS IN PSYCHOLOGY 6 巻 ( NOV ) 頁： 1712 2015年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Frontiers in Psychology

© 2015 Shikishima, Hiraishi, Yamagata, Ando and Okada. Why does decision making differ among individuals? People sometimes make seemingly inconsistent decisions with lower expected (monetary) utility even when objective information of probabilities and reward are provided. It is noteworthy, however, that a certain proportion of people do not provide anomalous responses, choosing the alternatives with higher expected utility, thus appearing to be more "rational." We investigated the genetic and environmental influences on these types of individual differences in decision making using a classical Allais problem task. Participants were 1,199 Japanese adult twins aged 20-47. Univariate genetic analysis revealed that approximately a third of the Allais problem response variance was explained by genetic factors and the rest by environmental factors unique to individuals and measurement error. The environmental factor shared between families did not contribute to the variance. Subsequent multivariate genetic analysis clarified that decision making using the expected utility theory was associated with general intelligence and that the association was largely mediated by the same genetic factor. We approach the mechanism underlying two types of "rational" decision making from the perspective of genetic correlations with cognitive abilities.

DOI： 10.3389/fpsyg.2015.01712

Why children differ in motivation to learn: Insights from over 13,000 twins from 6 countries 査読有り国際共著国際誌

Kovas Yulia, Garon-Carrier Gabrielle, Boivin Michel, Petrill Stephen A., Plomin Robert, Malykh Sergey B., Spinath Frank, Murayama Kou, Ando Juko, Bogdanova Olga Y., Brendgen Mara, Dionne Ginette, Forget-Dubois Nadine, Galajinsky Eduard V., Gottschling Juliana, Guay Frederic, Lemelin Jean-Pascal, Logan Jessica A. R., Yamagata Shinji, Shikishima Chizuru, Spinath Birgit, Thompson Lee A., Tikhomirova Tatiana N., Tosto Maria G., Tremblay Richard, Vitaro Frank

PERSONALITY AND INDIVIDUAL DIFFERENCES 80 巻頁： 51 - 63 2015年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Personality and Individual Differences

© 2015. Little is known about why people differ in their levels of academic motivation. This study explored the etiology of individual differences in enjoyment and self-perceived ability for several school subjects in nearly 13,000 twins aged 9-16 from 6 countries. The results showed a striking consistency across ages, school subjects, and cultures. Contrary to common belief, enjoyment of learning and children's perceptions of their competence were no less heritable than cognitive ability. Genetic factors explained approximately 40% of the variance and all of the observed twins' similarity in academic motivation. Shared environmental factors, such as home or classroom, did not contribute to the twin's similarity in academic motivation. Environmental influences stemmed entirely from individual specific experiences.

DOI： 10.1016/j.paid.2015.02.006

Heritability of decisions and outcomes of public goods games 査読有り国際誌

Hiraishi Kai, Shikishima Chizuru, Yamagata Shinji, Ando Juko

FRONTIERS IN PSYCHOLOGY 6 巻 ( MAR ) 頁： 373 2015年4月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Frontiers in Psychology

© 2015 Hiraishi, Shikishima, Yamagata and Ando. Prosociality is one of the most distinctive features of human beings but there are individual differences in cooperative behavior. Employing the twin method, we examined the heritability of cooperativeness and its outcomes on public goods games using a strategy method. In two experiments (Study 1 and Study 2), twin participants were asked to indicate 1) how much they would contribute to a group when they did not know how much the other group members were contributing, and 2) how much they would contribute if they knew the contributions of others. Overall, the heritability estimates were relatively small for each type of decision, but heritability was greater when participants knew that the others had made larger contributions. Using registered decisions in Study 2, we conducted five Monte Carlo simulations to examine genetic and environmental influences on the expected game payoffs. For the simulated one-shot game, the heritability estimates were small, comparable to those of game decisions. For the simulated iterated games, we found that the genetic influences first decreased, then increased as the numbers of iterations grew. The implication for the evolution of individual differences in prosociality is discussed.

DOI： 10.3389/fpsyg.2015.00373

Personality traits show differential relations with anxiety and depression in a nonclinical sample 査読有り国際共著国際誌

Takahashi Y., Roberts B., Yamagata S., Kijima N.

Psychologia 58 巻 ( 1 ) 頁： 15 - 26 2015年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Psychologia

This study examined how the personality traits of behavioral inhibition and behavioral activation contribute to the development of anxiety and depression. We used two-wave short-term longitudinal data from 319 students. Data collections were two months apart. Personality traits were assessed using Gray's Reinforcement Sensitivity Theory: Behavioral Inhibition and Activation Systems (BIS and BAS). After conirming simple correlations, hierarchical regressions were conducted to test how residual changes or unique variances in psychopathology were predicted by the personality traits. Findings revealed that high BIS sensitivity predicted both anxiety and depression, while low BAS sensitivity predicted only depression. These results suggest that hyperactive BIS functions as a predictor for general distress, and that hypoactive BAS functions as a unique predictor for depression.

DOI： 10.2117/psysoc.2015.15

基幹教育課題協学科目査読有り

古屋謙治, 大河内豊, 島田敬士, 田中岳, 野瀬健, 山形伸二

基幹教育紀要 = Bulletin of kikan education 1 巻頁： 63 - 69 2015年

米国の競争性の高い大学における入学者選抜査読有り

山形伸二, 繁桝算男

大学入試研究ジャーナル ( 24 ) 頁： 97 - 104 2014年3月

Culture Moderates the Genetic and Environmental Etiologies of Parenting: A Cultural Behavior Genetic Approach 査読有り国際共著国際誌

Shikishima Chizuru, Hiraishi Kai, Yamagata Shinji, Neiderhiser Jenae M., Ando Juko

SOCIAL PSYCHOLOGICAL AND PERSONALITY SCIENCE 4 巻 ( 4 ) 頁： 434 - 444 2013年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Social Psychological and Personality Science

A cultural behavior genetic approach was introduced as a prospective means to describe psychological differences between cultures. We compared genetic and environmental influences on remembered parenting for samples of twins from Japan and Sweden. Data were collected from 720 pairs of young adult Japanese twins and 824 pairs of adult Swedish twins using the Parental Bonding Instrument. In both samples, a very similar phenotypic factor structure was developed for maternal and paternal parenting. However, the genetic and environmental contributions were different. Parenting in Japan showed more genetic influences, whereas parenting in Sweden showed more shared environmental influences. Moreover, covariation among the six dimensions of parenting (i.e., maternal and paternal Warmth, Protectiveness, and Authoritarianism) was due to genetic correlations in Japan and to shared environmental correlations in Sweden. These results are consistent with the cultural psychology argument that parenting practices are child centered in Japan but parent centered in the West. © The Author(s) 2012.

DOI： 10.1177/1948550612460058

Inequality of opportunity in Japan: A behavioral genetic approach 査読有り国際誌

Yamagata, S, Nakamuro, M, Inui, T

RIETI Discussion Paper Series 13 巻 ( E-097 ) 頁： 1 - 18 2013年3月

Two Cohort and Three Independent Anonymous Twin Projects at the Keio Twin Research Center (KoTReC) 査読有り国際誌

Ando Juko, Fujisawa Keiko K., Shikishima Chizuru, Hiraishi Kai, Nozaki Mari, Yamagata Shinji, Takahashi Yusuke, Ozaki Koken, Suzuki Kunitake, Deno Minako, Sasaki Shoko, Toda Tatsushi, Kobayashi Kazuhiro, Sugimoto Yutaro, Okada Mitsuhiro, Kijima Nobuhiko, Ono Yutaka, Yoshimura Kimio, Kakihana Shinichiro, Maekawa Hiroko, Kamakura Toshimitsu, Nonaka Koichi, Kato Noriko, Ooki Syuichi

TWIN RESEARCH AND HUMAN GENETICS 16 巻 ( 1 ) 頁： 202 - 216 2013年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Twin Research and Human Genetics

The Keio Twin Research Center has conducted two longitudinal twin cohort projects and has collected three independent and anonymous twin data sets for studies of phenotypes related to psychological, socio-economic, and mental health factors. The Keio Twin Study has examined adolescent and adult cohorts, with a total of over 2,400 pairs of twins and their parents. DNA samples are available for approximately 600 of these twin pairs. The Tokyo Twin Cohort Project has followed a total of 1,600 twin pairs from infancy to early childhood. The large-scale cross-sectional twin study (CROSS) has collected data from over 4,000 twin pairs, from 3 to 26 years of age, and from two high school twin cohorts containing a total of 1,000 pairs of twins. These data sets of anonymous twin studies have mainly targeted academic performance, attitude, and social environment. The present article introduces the research designs and major findings of our center, such as genetic structures of cognitive abilities, personality traits, and academic performances, developmental effects of genes and environment on attitude, socio-cognitive ability and parenting, genes x environment interaction on attitude and conduct problem, and statistical methodological challenges and so on. We discuss the challenges in conducting twin research in Japan. Copyright © The Authors 2013.

DOI： 10.1017/thg.2012.131

Bidirectional influences between maternal parenting and children’s peer problems: A longitudinal monozygotic twin difference study. 査読有り国際誌

Yamagata, S, Takahashi, Y, Ozaki, K, Fujisawa, K. K, Nonaka, K, Ando, J

Developmental Science 16 巻 ( 2 ) 頁： 249 - 259 2013年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Developmental Science

This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin difference scores revealed that authoritative parenting (the presence of consistent discipline and lack of harsh parenting) and peer problems simultaneously influenced each other. Authoritative parenting reduced peer problems, and peer problems increased authoritative parenting. Neither consistent discipline nor harsh parenting alone was associated with peer problems. These results suggest that maternal authoritative parenting works protectively in regard to children's peer problems, and peer problems can evoke such effective parenting. © 2012 Blackwell Publishing Ltd.

DOI： 10.1111/desc.12021

Hyperactivity/Inattention Problems Moderate Environmental but Not Genetic Mediation Between Negative Parenting and Conduct Problems 査読有り国際誌

Fujisawa Keiko K., Yamagata Shinji, Ozaki Koken, Ando Juko

JOURNAL OF ABNORMAL CHILD PSYCHOLOGY 40 巻 ( 2 ) 頁： 189 - 200 2012年2月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Abnormal Child Psychology

This study investigated the association between negative parenting (NP) and conduct problems (CP) in 6-year-old twins, taking into account the severity of hyperactivity/inattention problems (HIAP). Analyses of the data from 1,677 pairs of twins and their parents revealed that the shared environmental covariance between NP and CP was moderated by the level of HIAP but not by CP or NP, where the shared environmental covariance was larger in children with higher levels of HIAP than in children with lower levels of HIAP. The genetic covariance between NP and CP was not moderated by the level of HIAP, whereas it was larger in the group with lower levels of CP and NP than in the group with higher levels. These results suggest that severe HIAP strengthens shared environmental associations between NP and CP and that interventions focusing on the shared environmental component of NP would be effective for parents and children with severe HIAP. © Springer Science+Business Media, LLC 2011.

DOI： 10.1007/s10802-011-9559-6

Genetic and environmental relationships between head circumference growth in the first year of life and sociocognitive development in the second year: a longitudinal twin study 査読有り国際誌

Fujisawa Keiko K., Ozaki Koken, Suzuki Kunitake, Yamagata Shinji, Kawahashi Ikko, Ando Juko

DEVELOPMENTAL SCIENCE 15 巻 ( 1 ) 頁： 99 - 112 2012年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Developmental Science

Although growth in head circumference (HC) during infancy is known to predict later childhood outcomes, the mechanisms underlying this association with later sociocognitive abilities remain undetermined. Thus, using a sample of 241 pairs of normally developing Japanese twins, this study investigated the underpinnings of the association between HC growth (difference between HC at birth and at 10months) and sociocognitive abilities at 19months as measured by 10 items from the M-CHAT. Phenotypic correlations between HC at birth and sociocognitive abilities and between HC growth and sociocognitive abilities were marginal and not significant. However, multivariate genetic analyses using Cholesky decomposition revealed that genetic influences on HC growth and those on sociocognitive abilities were negatively associated. On the other hand, shared and nonshared environmental influences on HC growth were positively associated with influences on sociocognitive abilities. Genetic and environmental influences on HC at birth were not significantly associated with influences on sociocognitive abilities. These results help to clarify the role of brain growth during infancy in the subsequent development of sociocognitive abilities and highlight the importance of examining the different roles of genetic and environmental influences in studies of these areas. © 2011 Blackwell Publishing Ltd.

DOI： 10.1111/j.1467-7687.2011.01097.x

Grayの行動抑制系と不安・抑うつ : 双生児法による4つの因果モデルの検討査読有り

山形伸二, 高橋雄介, 木島伸彦

パーソナリティ研究 20 巻 ( 2 ) 頁： 110 - 117 2011年11月

記述言語：日本語掲載種別：研究論文（学術雑誌）出版者・発行元：日本パーソナリティ心理学会

本研究は，Grayが提案した気質である行動抑制系（BIS）と抑うつ，不安感情の間の因果の方向性について検討した。双生児424組のデータに対し，横断的家族データから変数間の因果関係を推測する方法である「因果の方向性モデル」を適用した。（1）BISが抑うつ，不安に影響を与える，（2）抑うつ，不安がBISに影響を与える，（3）両者が相互に影響を与え合う，（4）両者の相関関係は第三変数による擬似相関である，という4つの可能性を検討したところ，抑うつ，不安いずれについてもBISが影響を与えるとするモデルの当てはまりが最もよかった。次に，抑うつ，不安の間の因果の方向性を検討したところ，抑うつと不安は相互に正の影響を与え合うとするモデルの当てはまりが最もよかった。以上より，BISが様々な精神病理の素因であるとする従来の考え方が支持され，また抑うつ，不安一方への介入が他方の改善にも有用である可能性が示唆された。

DOI： 10.2132/personality.20.110