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How do genetic and environmental processes affect empathy during early adolescence? This study illuminated this question by examining the aetiology of empathy with the aetiology of other personality characteristics.Israeli twin adolescents rated their empathy and personality at ages 11 (N = 1176) and 13 (N = 821) (733 families, 51.4% females). Parents rated adolescents' emotional empathy. Adolescents performed an emotion recognition task, indicating cognitive empathy.Using a cross-validated statistical learning algorithm, this study found emotional and cognitive "empathic personality profiles," which describe and predict self-reported empathy from nuanced Big-Five personality characteristics, or "nuances" (i.e., individual items). These profiles predicted empathy moderately (RThis study demonstrates how addressing the complexity of individuals' personalities can inform adolescents' empathy development.

Our aim was to adapt and validate a Brazilian Portuguese version of the Twin Relationship Questionnaire developed by Fortuna et al. (2010) and validated by H. Segal and Knafo-Noam (2019) in Israel. The respondents were 862 Brazilian mothers of twins ( N = 1724 twins) with mean age of 35 years (SD = 6.1). The majority of the sample lived in the Southeast (61.8%) or in the South (24.5%) of Brazil. We conducted a Multilevel Confirmatory Factor Analysis with the pair of twins as second level variable, and the five-factor structure (closeness, dependence, conflict, dominance, and rivalry) proposed by the original validation study of H. Segal and Knafo-Noam (2019) was confirmed. The final model retained 15 items out of 22 proposed in the original version of the questionnaire. Although the TRQ-BR has fewer items, the accuracy compared to the original questionnaire was maintained. Mixed Model Analysis (LMM) of TRQ scores were used to investigate twins’ relationships as a function of zygosity, age groups, and sex in order to provide evidence of convergent validity of the instrument. As expected, mothers perceived monozygotic twins (MZ) as more depedent than dizygotic twins (DZ). Furthermore, male twin pairs were considered more conflictive when compared to female twins. The present study showed that TRQ-BR is an adequate instrument for research purposes in the Brazilian population. It can also be useful for applied areas such as clinical and educational fields.

Background Body mass index (BMI) shows strong continuity over childhood and adolescence and high childhood BMI is the strongest predictor of adult obesity. Genetic factors strongly contribute to this continuity, but it is still poorly known how their contribution changes over childhood and adolescence. Thus, we used the genetic twin design to estimate the genetic correlations of BMI from infancy to adulthood and compared them to the genetic correlations of height. Methods We pooled individual level data from 25 longitudinal twin cohorts including 38,530 complete twin pairs and having 283,766 longitudinal height and weight measures. The data were analyzed using Cholesky decomposition offering genetic and environmental correlations of BMI and height between all age combinations from 1 to 19 years of age. Results The genetic correlations of BMI and height were stronger than the trait correlations. For BMI, we found that genetic correlations decreased as the age between the assessments increased, a trend that was especially visible from early to middle childhood. In contrast, for height, the genetic correlations were strong between all ages. Age-to-age correlations between environmental factors shared by co-twins were found for BMI in early childhood but disappeared altogether by middle childhood. For height, shared environmental correlations persisted from infancy to adulthood. Conclusions Our results suggest that the genes affecting BMI change over childhood and adolescence leading to decreasing age-to-age genetic correlations. This change is especially visible from early to middle childhood indicating that new genetic factors start to affect BMI in middle childhood. Identifying mediating pathways of these genetic factors can open possibilities for interventions, especially for those children with high genetic predisposition to adult obesity. This study was conducted within the CODATwins project. Support for collaborators: Colorado Twin Registry is funded by NIDA funded center grant DA011015, & Longititudinal Twin Study HD10333; Author Huibregtse is supported by National Institute on Drug Abuse (5T32DA017637) and National Institute on Aging (5T32AG052371). Finnish Twin Cohort is supported by the Academy of Finland (grants 312073 and 336823) and the Sigrid Juselius Foundation. Michigan State University Twin Registry was supported by National Institute of Mental Health (NIMH) (R01-MH081813, R01-MH0820–54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01, 1R01-MH118848-01), Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD) (R01-HD066040) and MSU Foundation (11-SPG-2518). PETS was funded by the Australian National Health and Medical Research Council (grant numbers 437015 and 607358); the Bonnie Babes Foundation (grant number BBF20704); the Financial Markets Foundation for Children (grant number 032-2007); and the Victorian Government’s Operational Infrastructure Support Program. We acknowledge The Swedish Twin Registry for access to data. The Swedish Twin Registry is managed by Karolinska Institutet and receives funding through the Swedish Research Council under the grant no 2017-00641. TEDS was supported by a program grant to RP from the UK Medical Research Council (MR/M021475/1 and previously G0901245), with additional support from the US National Institutes of Health (AG046938). The West Japan Twins and Higher Order Multiple Births Registry was supported by Grant-in-Aid for Scientific Research (B) (grant number 20H04019) from the Japan Society for the Promotion of Science. Open Access funding provided by University of Helsinki including Helsinki University Central Hospital.

Accumulating research suggests the structure of psychopathology is best represented by continuous higher-order dimensions, including a general dimension, p-factor, and more specific dimensions, e.g., residualized externalizing and internalizing factors. Here, we aimed to 1) replicate p in early childhood; 2) externally validate the factors with key constructs of psychological functioning; 3) examine stability and change of genetic and environmental influences on the psychopathology factors from early-to mid-childhood; 4) examine the factors’ predictive utility; and 5) test whether the factors can be predicted by early life measures (e.g., neonatal complications). The Longitudinal Israeli Study of Twins from age 3 to 9 was used for the analyses. Mothers reported on developmental problems, pregnancy and neonatal conditions, and filled in questionnaires on each twin’s externalizing and internalizing symptoms. Cognitive ability was assessed in the lab at age 6.5 and personality traits, self-esteem, and life satisfaction were self-reported by the twins at ages 11-13. A bifactor model that included p and externalizing and internalizing factors fit the data best and associations between p, cognitive ability, and personality were replicated. Longitudinal twin analyses indicated that p is highly heritable (64-73%) with a substantial proportion of the genetic influences stable from age 3. The residualized internalizing and externalizing factors were also highly heritable. Higher p predicted developmental problems at age 8-9 and lower self-esteem at age 11. Early life measures were not strongly associated with psychopathology. Our results show that p is discernible in early childhood, highly heritable, and prospectively associated with negative outcomes.General Scientific SummaryThe general psychopathology factor is discernible in early childhood, highly heritable, with genetic influences contributing to both stability and change, and prospectively associated with developmental problems and lower self-esteem. Early life measures, such as birth complications or hospitalizations during the first year of life, were not strong predictors of the general psychopathology factor or the residualized externalizing and internalizing factors.

Twin relationships have a significant effect on the twins’ life and their families. In the first comprehensive study of this topic, our purpose was to examine the developmental courses of four dyadic dimensions of twins’ relationships: closeness, dependence, conflict and rivalry, and the impact of zygosity and parenting on their relationships. Parents reported on their twins’ relationships ( N = 1547 mothers and 536 fathers with data from at least one of four measurement points from 3 to 8–9 years of age). The sample included 322 monozygotic twin dyads (sharing virtually 100% of their genes), and 1194 dizygotic twin dyads (sharing 50% of their genetic variance, on average). Our findings indicated that closeness and dependence decreased while rivalry increased through childhood. Dependence and rivalry also presented quadratic change. The twins’ conflict increased only for dizygotic twins. As expected, we found that the twins’ closeness and dependence were highly associated, as did the associations between conflict and rivalry. The mostly nonsignificant associations of closeness with conflict and rivalry reinforced the notion that they are not bi-polar opposites. However, dependence was positively related to the twins’ conflict and rivalry. A zygosity effect was also evident as monozygotic twins had higher levels of closeness and dependence than dizygotic twins through childhood, but there was no significant difference in the levels of their conflict and rivalry. In congruence with family system theories, parental positivity predicted the twins’ closeness and dependence, and parental negativity predicted the twins’ dependence, conflict and rivalry. The results were discussed in light of an evolutionary perspective and the twins’ developmental challenges through childhood.

This study tested the effect of personal values (motivation) and sustained attention (cognitive ability) on children's helping behavior.Children (N = 162, age range 8-9 years, mean = 8.81, SD = 0.43) completed value ranking and go/no-go tasks, and their helping behavior was examined.Children who valued self-transcendence over self-enhancement helped more than others. Surprisingly, children's lack of sustained attention was associated with more helping among those who valued self-transcendence over self-enhancement or openness-to-change over conservation values. Valuing both self-transcendence and openness-to-change was also associated with more helping.Children are more likely to help others if they value self-transcendence and openness to change. Notably, children's tendency to act upon these values may be facilitated (rather than obstructed by) low attention skills.

This study examines the hypothesis that temperamental (dis)similarity is associated with twin relationship quality. In a longitudinal study that followed 322 monozygotic twins (who share close to 100% of their genes) and 1199 dizygotic twins (who on average, share 50% of their segregating genes) throughout childhood, mothers ( N = 1547) and fathers ( N = 536) reported on their twins’ relationships on at least one of four measurement points when the twins were between 3 and 8–9 years of age. Mothers also reported on the twins’ temperament. Negative associations were found between reports by both parents on the twins’ closeness and their temperament difference throughout childhood, while positive associations were found between twins’ conflict and their temperament difference in late childhood. Latent growth modeling indicated that the association between temperament differences and the twins’ mother-reported closeness was evident beyond the effect of zygosity. A different pattern was found for twin conflict: the more the twins differed in their temperament (specifically negative emotionality) with age, the more the conflict between them increased. Our findings support the hypothesis that personality similarities can contribute to positive relationships from early childhood, and vice versa, beyond the effect of genetic similarity.

Despite the importance of self-control for well-being and adjustment, its development from early childhood to early adolescence has been relatively understudied. We addressed the development of mother-reported self-control in what is likely the largest and longest longitudinal twin study of the topic to this day (N = 1889 individual children with data from at least one of five waves: ages 3, 5, 6.5, 8-9 and 11 years). We examined rank-order change in self-control from early childhood to early adolescence, genetic and environmental contributions to variance in the trait and differential developmental trajectories. The relative contribution of genetic and environmental factors to change and stability was also examined. Results point at middle childhood as a period of potential transition and change. During this period the rank-order stability of self-control increases, heritability rates substantially rise, and a cross-over occurs in two of the self-control trajectories. Nonadditive genetic effects contribute to both stability and change in self-control while the nonshared environment contributes mostly to change, with no effect for the shared environment. Our findings suggest that new genetic factors, that emerge around age 6.5 and whose effect on self-control is carried on along development, may partially account for changes in self-control around late middle childhood, and explain the growing stability in the trait approaching early adolescence. We discuss the implications of the special role of middle childhood for self-control development.

The Longitudinal Israeli Study of Twins (LIST) focuses on the developmental, genetic and environmental contributions to individual differences in children’s and adolescents’ social behavior. Key variables have been empathy, prosocial behavior, temperament and values. Another major goal of LIST has been to study gene–environment correlations, mainly concerning parenting. LIST includes 1657 families of Hebrew-speaking Israeli twins who have participated at least once in the study. Children’s environment and their development are assessed in a multivariate, multimethod fashion, including observed, parent-reported and self-reported data. The current article summarizes and updates recent findings from LIST. For example, LIST provided evidence for the heritability of human values with the youngest sample to date, and the first genetic investigation of adolescents’ identity formation. Finally, future aims of LIST are discussed.

Objective: To analyze how parental education modifies the genetic and environmental variances of body mass index (BMI) from infancy to old age in three geographic-cultural regions. Methods: A pooled sample of 29 cohorts including 143 499 twin individuals with information on parental education and BMI from 1 to 79 years (299 201 BMI measures) was analyzed by genetic twin modeling. Results: Until 4 years of age, parental education was not consistently associated with BMI. Thereafter, higher parental education was associated with lower BMI in males and females. Total and additive genetic variances of BMI were smaller in the offspring of highly educated parents than in those whose parents had low education. Especially in North American and Australian children, environmental factors shared by co-twins also contributed to the higher BMI variation in the low educational category. In Europe and East Asia, the associations of parental education with mean BMI and BMI variance were weaker than in North America and Australia. Conclusions: Lower parental education is associated with higher mean and larger genetic variance of BMI after early childhood, especially in the obesogenic macro-environment. The interplay between genetic predisposition, childhood social environment and macro-social context is important for socio-economic differences in BMI.

There is a growing body of literature linking religious attendance to prosocial behavior (PB). The main purposes of the present study were to estimate genetic and environmental influences on the frequency of religious attendance (FRA) and to explore whether and how FRA moderates genetic and/or environmental influences on PB. As part of the Nigerian Twin and Sibling Study, 2860 (280 monozygotic male, 417 monozygotic female, 544 dizygotic male, 699 dizygotic female, and 920 opposite-sex dizygotic) twins (mean age = 14.2 years; SD = 1.7 years; age range = 12–18 years) completed a questionnaire regarding FRA and a PB scale. Similar to the findings from western twin samples, FRA showed substantial shared environmental influences of 74% (95% CI = 69%, 78%), with absence of genetic effects. The phenotypic correlation between FRA and PB was modest but positive and significant (r = .12; p < .01), suggesting that PB is higher among more frequent attenders than among less frequent attenders. The results of gene–environment (G × E) interaction model-fitting analysis revealed that FRA changed individual environmental experiences rather than genetic effects on PB such that while genetic variance was stable, non-shared environmental variance declined, leading the total phenotypic variance of PB to decrease with increasing levels of religious attendance.

Loos, Ruth J F/0000-0002-8532-5087; Huibregtse, Brooke M./0000-0003-0977-7249; Kandler, Christian/0000-0002-9175-235X; Hjelmborg, Jacob/0000-0001-9630-9149; mangino, massimo/0000-0002-2167-7470; Siribaddana, Sisira/0000-0001-5821-2557; Plomin, Robert/0000-0002-0756-3629; Latvala, Antti/0000-0001-5695-117X; Kaprio, Jaakko/0000-0002-3716-2455; Willemsen, Gonneke/0000-0003-3755-0236; Tan, Qihua/0000-0003-3194-0030; Pahlen, Shandell/0000-0003-0753-4155; Pedersen, Nancy/0000-0001-8057-3543; Haworth, Claire/0000-0002-8608-289X; Nistico, Lorenza/0000-0003-1805-6240; Skytthe, Axel/0000-0002-8629-4913; van Beijsterveldt, Toos/0000-0002-6617-4201; Rebato, Esther/0000-0003-1221-8501; Li, Lintao/0000-0002-0604-9660; Bartels, Meike/0000-0002-9667-7555; Silventoinen, Karri/0000-0003-1759-3079; Cunha Oliveira, Vinicius/0000-0002-8658-3774; Sund, Reijo/0000-0002-6268-8117; Sodemann, Morten/0000-0001-8992-2500; Rasmussen, Finn/0000-0001-7915-7809; Harden, Kathryn/0000-0002-1557-6737; Medda, Emanuela/0000-0003-4837-4549; Kyvik, Kirsten Ohm/0000-0003-2981-0245; Colodro Conde, Lucia/0000-0002-9004-364X WOS: 000517442200060 PubMed: 31364586 The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m(2)) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural-geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status. Academy of FinlandAcademy of Finland [266592, 100499, 205585, 118555, 141054, 265240, 263278, 264146]; Osaka University's International Joint Research Promotion Program; Centre of Research Excellence Grant from the National Health and Medical Research CouncilNational Health and Medical Research Council of Australia [1079102]; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01 HD068435, R01 MH062375, 1R01ESO15150-01, R21 AG039572]; National Medical Research Council Research Fellowship; California Tobacco-Related Disease Research ProgramUniversity of California System [7RT-0134H, 8RT-0107H, 6RT-0354H]; National Institute on AgingUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Aging (NIA) [1RO1-AG13662-01A2]; Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) [340-2013-5867]; Swedish Heart-Lung FoundationSwedish Heart-Lung Foundation; Swedish Asthma and Allergy Association's Research Foundation; Special Fund for Health Scientific Research in the Public Welfare, China [201502006]; NIDAUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Drug Abuse (NIDA) [DA011015, HD10333]; National Program for Research Infrastructure 2007 from the Danish Agency for Science, Technology and Innovation; Research Council for Health and Disease; Velux Foundation; US National Institute of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [P01 AG08761]; Fund of Scientific Research, FlandersFWO; ENGAGE - European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007 [201413]; National Institute of Alcohol Abuse and AlcoholismUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Alcohol Abuse & Alcoholism (NIAAA) [AA-12502, AA-00145, AA-09203]; Academy of Finland Center of Excellence in Complex Disease GeneticsAcademy of Finland [213506, 129680]; Cancer Research UKCancer Research UK [C1418/A7974]; W T Grant Foundation; University of London Central Research fund; Medical Research CouncilMedical Research Council UK (MRC) [G81/343, G120/635]; Economic and Social Research CouncilEconomic & Social Research Council (ESRC) [RES-000-22-2206]; Institute of Social Psychiatry [06/07-11]; Leverhulme Research FellowshipLeverhulme Trust [RF/2/RFG/2008/0145]; Goldsmiths, University of London; UK Medical Research CouncilMedical Research Council UK (MRC) [MR/M021475/1, G0901245]; National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London; NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01AG053217, RC2 HL103416]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [81125007]; Global Research Network Program of the National Research Foundation [NRF 2011-220-E00006]; European Research Council (ERC)European Research Council (ERC) [240994]; Michigan State University; National Institute of Mental Health (NIMH)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01, 1R01-MH118848-01]; Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD) [R01-HD066040]; MSU Foundation [11-SPG-2518]; Fundacion Seneca, Regional Agency for Science and Technology, Murcia, Spain [08633/PHCS/08, 15302/PHCS/10, 19479/PI/14]; Ministry of Science and Innovation, SpainSpanish Government [PSI2009-11560, PSI2014-56680-R]; MagW/ZonMW [904-61-090, 985-10-002, 912-10-020, 904-61-193, 480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192]; European Research CouncilEuropean Research Council (ERC) [ERC-230374]; JSPS KAKENHI JP [23593419, 24792601, 26671010, 24590695, 26293128, 16K15385, 16K15978, 16K15989, 16H03261]; Australian National Health and Medical Research CouncilNational Health and Medical Research Council of Australia [437015, 607358]; Bonnie Babes Foundation [BBF20704]; Financial Markets Foundation for Children [032-2007]; Victorian Government; Portuguese agency for research (The Foundation for Science and Technology [FCT]) [POCI/DES/56834/2004]; Wellcome TrustWellcome Trust; Medical Research CouncilMedical Research Council UK (MRC); European UnionEuropean Union (EU); National Institute for Health Research (NIHR)National Institute for Health Research (NIHR); King's College London; Fonds Quebecois de la Recherche sur la Societe et la CultureFQRNT; Fonds de la Recherche en Sante du QuebecFonds de la Recherche en Sante du Quebec; Social Science and Humanities Research Council of Canada; National Health Research Development Program; Canadian Institutes for Health ResearchCanadian Institutes of Health Research (CIHR); Sainte-Justine Hospital's Research Center; Canada Research Chair ProgramCanada Research Chairs; National Research Foundation of KoreaNational Research Foundation of Korea [NRF-371-2011-1 B00047]; Swedish Research CouncilSwedish Research Council [2017-00641]; UK Biotechnology and Biological Sciences Research CouncilBiotechnology and Biological Sciences Research Council (BBSRC) [31/D19086]; MRCMedical Research Council UK (MRC) [MR/M021475/1]; Krkkale University [2009/43]; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114C117]; National Institute of Mental HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [R01 MH58354]; National Institute of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [NIA R01 AG018384, R01 AG018386, R01 AG022381, R01 AG022982]; VA San Diego Center of Excellence for Stress and Mental Health; Cooperative Studies Program of the Office of Research & Development of the United States Department of Veterans Affairs; Japan Society for the Promotion of ScienceMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of Science [15H05105]; Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust; Stockholm County Council (ALF-projects)Stockholm County Council; Twins, a nonprofit Association for Scientific Research in Multiple Births (Belgium); [5T32DA017637]; [5T32AG052371] This study was conducted within the CODATwins project (Academy of Finland #266592). K Silventoinen is supported by Osaka University's International Joint Research Promotion Program. This research was facilitated through access to Twins Research Australia, a national resource supported by a Centre of Research Excellence Grant (ID: 1079102), from the National Health and Medical Research Council. The Boston University Twin Project is funded by grants (#R01 HD068435 #R01 MH062375) from the National Institutes of Health to K. Saudino. Paulo Ferreira is funded by a National Medical Research Council Research Fellowship. California Twin Program was supported by The California Tobacco-Related Disease Research Program (7RT-0134H, 8RT-0107H, 6RT-0354H) and the National Institutes of Health (1R01ESO15150-01).; The Carolina African American Twin Study of Aging (CAATSA) was funded by a grant from the National Institute on Aging (grant 1RO1-AG13662-01A2) to K. E. Whitfield. The CATSS-Study is supported by the Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Swedish Heart-Lung Foundation and the Swedish Asthma and Allergy Association's Research Foundation.; Chinese National Twin Registry is funded by Special Fund for Health Scientific Research in the Public Welfare (Project No: 201502006), China. Colorado Twin Registry is funded by NIDA-funded center grant DA011015, & Longitudinal Twin Study HD10333; Author Huibregtse is supported by 5T32DA017637 and 5T32AG052371. Danish Twin Registry is supported by the National Program for Research Infrastructure 2007 from the Danish Agency for Science, Technology and Innovation, The Research Council for Health and Disease, the Velux Foundation and the US National Institute of Health (P01 AG08761). Since its origin, the East Flanders Prospective Survey has been partly supported by grants from the Fund of Scientific Research, Flanders and Twins, a nonprofit Association for Scientific Research in Multiple Births (Belgium). Data collection and analyses in Finnish twin cohorts have been supported by ENGAGE - European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145 and AA-09203 to R J Rose, the Academy of Finland Center of Excellence in Complex Disease Genetics (grant numbers: 213506, 129680), and the Academy of Finland (grants 100499, 205585, 118555, 141054, 265240, 263278 and 264146 to J Kaprio). Gemini was supported by a grant from Cancer Research UK (C1418/A7974). Waves 1-3 of Genesis 12-19 were funded by the W T Grant Foundation, the University of London Central Research fund and a Medical Research Council Training Fellowship (G81/343) and Career Development Award (G120/635) to Thalia C. Eley. Wave 4 was supported by grants from the Economic and Social Research Council (RES-000-22-2206) and the Institute of Social Psychiatry (06/07-11) to Alice M. Gregory, who was also supported at that time by a Leverhulme Research Fellowship (RF/2/RFG/2008/0145). Wave 5 was supported by funding to Alice M. Gregory from Goldsmiths, University of London. T. C. Eley is partly funded by a program grant from the UK Medical Research Council (MR/M021475/1).; This study presents independent research [partly] funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King's College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. The Minnesota Twin Registry (MTR) acknowledges support from NIH grant R01AG053217. Guangzhou Twin Eye Study is supported by National Natural Science Foundation of China (grant #81125007). Anthropometric measurements of the Hungarian twins were supported by Medexpert Ltd., Budapest, Hungary. Korean Twin-Family Register was supported by the Global Research Network Program of the National Research Foundation (NRF 2011-220-E00006). Longitudinal Israeli Study of Twins was funded by the Starting Grant no. 240994 from the European Research Council (ERC) to Ariel Knafo. The Michigan State University Twin Registry has been supported by Michigan State University, as well as grants R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01 and 1R01-MH118848-01 from the National Institute of Mental Health (NIMH), R01-HD066040 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD) and 11-SPG-2518 from the MSU Foundation. The content of this paper is solely the responsibility of the authors and does not necessarily represent the official views of the NIMH, the NICHD or the National Institutes of Health. The Murcia Twin Registry is supported by Fundacion Seneca, Regional Agency for Science and Technology, Murcia, Spain (08633/PHCS/08, 15302/PHCS/10 & 19479/PI/14) and Ministry of Science and Innovation, Spain (PSI2009-11560 & PSI2014-56680-R). The NAS-NRC Twin Registry acknowledges financial support from the National Institutes of Health grant number R21 AG039572. Netherlands Twin Register acknowledges the Netherlands Organization for Scientific Research (NWO) and MagW/ZonMW grants 904-61-090, 985-10-002, 912-10-020, 904-61-193,480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192; VU University's Institute for Health and Care Research (EMGO+); the European Research Council (ERC-230374), the Avera Institute, Sioux Falls, South Dakota (USA). Osaka University Aged Twin Registry is supported by grants from JSPS KAKENHI JP (23593419, 24792601, 26671010, 24590695, 26293128, 16K15385, 16K15978, 16K15989, 16H03261). PETS was supported by grants from the Australian National Health and Medical Research Council (grant numbers 437015 and 607358 to JC, and RS), the Bonnie Babes Foundation (grant number BBF20704 to JMC), the Financial Markets Foundation for Children (grant no. 032-2007 to JMC), and by the Victorian Government's Operational Infrastructure Support Program.; Madeira data comes from the following project: Genetic and environmental influences on physical activity, fitness and health: the Madeira family study Project reference: POCI/DES/56834/2004 Founded by the Portuguese agency for research (The Foundation for Science and Technology [FCT]). TwinsUK receives funding from the Wellcome Trust, Medical Research Council and European Union.; TwinsUK and M. Mangino are supported by the National Institute for Health Research (NIHR)-funded BioResource, Clinical Research Facility and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust in partnership with King's College London. The Quebec Newborn Twin Study acknowledges financial support from the Fonds Quebecois de la Recherche sur la Societe et la Culture, the Fonds de la Recherche en Sante du Quebec, the Social Science and Humanities Research Council of Canada, the National Health Research Development Program, the Canadian Institutes for Health Research, Sainte-Justine Hospital's Research Center, and the Canada Research Chair Program (Michel Boivin). South Korea Twin Registry is supported by National Research Foundation of Korea (NRF-371-2011-1 B00047). We acknowledge The Swedish Twin Registry for access to data. The Swedish Twin Registry is managed by Karolinska Institutet and receives funding through the Swedish Research Council under the grant no. 2017-00641.; The Twins Early Development Study (TEDS) is supported by a program grant (G0901245) from the UK Medical Research Council and the work on obesity in TEDS is supported in part by a grant from the UK Biotechnology and Biological Sciences Research Council (31/D19086). Currently TEDS is supported by MRC grant 'MR/M021475/1'. The Texas Twin Project is currently funded by grant R01HD083613 from the National Institutes of Health. S. Y. oncel and F. Aliev are supported by Krkkale University Research Grant: KKU, 2009/43 and TUBITAK grant 114C117. The University of Southern California Twin Study is funded by a grant from the National Institute of Mental Health (R01 MH58354). Washington State Twin Registry (formerly the University of Washington Twin Registry) was supported in part by grant NIH RC2 HL103416 (D. Buchwald, PI). Vietnam Era Twin Study of Aging was supported by National Institute of Health grants NIA R01 AG018384, R01 AG018386, R01 AG022381 and R01 AG022982, and, in part, with resources of the VA San Diego Center of Excellence for Stress and Mental Health. The Cooperative Studies Program of the Office of Research & Development of the United States Department of Veterans Affairs has provided financial support for the development and maintenance of the Vietnam Era Twin (VET) Registry. The content of this paper is solely the responsibility of the authors and does not necessarily represent the official views of the NIA/NIH, or the VA. The West Japan Twins and Higher Order Multiple Births Registry was supported by Grant-in-Aid for Scientific Research (B) (grant number 15H05105) from the Japan Society for the Promotion of Science.

Think about what is important to you in your life – think about your values! This article explains how the values of people around the world are similar and different. We present the circle of values, which shows how people around the world understand ten basic values: universalism, benevolence, tradition, conformity, security, power, achievement, hedonism, stimulation, and self-direction. For a long time, scientists thought that values were an adult thing, and that children could not understand values very well. But children have values, too! The circle of values explains how our values guide us in life: We often take action for things we find important. For example, we embark on adventures if we value stimulation, but we stay safe if we value security. Finally, we will describe an experiment in which children shared chocolate coins or kept them for themselves, and we provide a link to a web page where you can test your own values.

Delayed gratification is the ability to postpone an immediate gain in favor of greater and later reward. Although delayed gratification has been studied extensively, little is known about the motivation behind children's decisions. Since values are cognitive representations of individuals' motivations, which serve to guide behavior, we studied the relationship between children's values and delayed gratification. Two main distinct motivations overlapping with values may underlie this decision: conservation - the desire to reduce uncertainty and preserve the status quo, and self-enhancement - the desire to maximize resources and profit for the self. Accordingly, we hypothesized that conservation values would relate to children's preference to hold on to what is given as soon as possible, and that self-enhancement values would relate to children's preference for delaying gratification. Seven-year old children (N = 205) ranked their values with the Picture-Based Values Survey (Doring et al., 2010) as part of the Longitudinal Israeli Study of Twins (LIST) (Avinun and Knafo, 2013). The children also played a decision-making animation game that included delayed gratification decisions. In support of our hypotheses, greater delayed gratification related negatively to conservation values, specifically to security and tradition, and related positively to self-enhancement values, especially power and achievement. This is one of the first demonstrations that children's values relate meaningfully to their behaviors.

Loos, Ruth J F/0000-0002-8532-5087; Kaprio, Jaakko/0000-0002-3716-2455; Huibregtse, Brooke M./0000-0003-0977-7249; de Freitas, Duarte Luis/0000-0001-6642-3370; Aliev, Fazil/0000-0001-8357-4699; Medda, Emanuela/0000-0003-4837-4549; Bartels, Meike/0000-0002-9667-7555; Latvala, Antti/0000-0001-5695-117X; Sund, Reijo/0000-0002-6268-8117; Rebato, Esther/0000-0003-1221-8501; Silventoinen, Karri/0000-0003-1759-3079; Aaltonen, Sari/0000-0002-2873-4263; Nistico, Lorenza/0000-0003-1805-6240; Knafo-Noam, Ariel/0000-0003-0613-1960; van Beijsterveldt, Toos/0000-0002-6617-4201; Harden, Kathryn/0000-0002-1557-6737; Willemsen, Gonneke/0000-0003-3755-0236; Pahlen, Shandell/0000-0003-0753-4155 WOS: 000465255700021 PubMed: 30950584 Objective The objective of this study was to analyze how parental education modifies the genetic and environmental variances of BMI from infancy to old age in three geographic-cultural regions. Methods A pooled sample of 29 cohorts including 143,499 twin individuals with information on parental education and BMI from age 1 to 79 years (299,201 BMI measures) was analyzed by genetic twin modeling. Results Until 4 years of age, parental education was not consistently associated with BMI. Thereafter, higher parental education level was associated with lower BMI in males and females. Total and additive genetic variances of BMI were smaller in the offspring of highly educated parents than in those whose parents had low education levels. Especially in North American and Australian children, environmental factors shared by co-twins also contributed to the higher BMI variation in the low education level category. In Europe and East Asia, the associations of parental education with mean BMI and BMI variance were weaker than in North America and Australia. Conclusions Lower parental education level is associated with higher mean BMI and larger genetic variance of BMI after early childhood, especially in the obesogenic macro-environment. The interplay among genetic predisposition, childhood social environment, and macro-social context is important for socioeconomic differences in BMI. Collaborative Project of Development of Anthropometrical Measures in Twins (Academy of Finland) [266592]; Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social and Medical Sciences Framework Grant [340-2013-5867]; Stockholm County Council (ALF projects)Stockholm County Council; Swedish Heart-Lung FoundationSwedish Heart-Lung Foundation; Swedish Asthma and Allergy Association's Research Foundation; Netherlands Organization for Scientific ResearchNetherlands Organization for Scientific Research (NWO); MagW/ZonMW [904-61-090, 985-10-002, 912-10-020, 904-61-193, 480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie-56-464-14192]; Vrije University's Institute for Health and Care Research; European Research Council (ERC)European Research Council (ERC) [230374]; Avera Institute, Sioux Falls, South Dakota; European Network for Genetic and Genomic Epidemiology (ENGAGE) [FP7-HEALTH-F4-2007, 201413]; National Institute of Alcohol Abuse and AlcoholismUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Alcohol Abuse & Alcoholism (NIAAA) [AA-12502, AA-00145, AA-09203]; Academy of Finland Center of Excellence in Complex Disease GeneticsAcademy of Finland [213506, 129680]; Academy of FinlandAcademy of Finland [100499, 205585, 118555, 141054, 265240, 264146, 312073]; Fund of Scientific Research, FlandersFWO; Twins, a nonprofit Association for Scientific Research in Multiple Births (Belgium); Cancer Research UKCancer Research UK [C1418/A7974]; European Union's Seventh Framework Programmes ENGAGE Consortium [HEALTH-F4-2007-201413]; Biobank Standardization and Harmonization for Research Excellence in the European Union [HEALTH-F4-2010-261433]; Kirikkale UniversityKirikkale University [2009/43]; Scientific and Technological Research Council of TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114C117]; Osaka University's International Joint Research Promotion Program; National Institutes of Health (NIH)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01HD068435, R01MH062375]; California Tobacco-Related Disease Research ProgramUniversity of California System [7RT-0134H, 8RT-0107H, 6RT-0354H]; NIHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [1R01ESO15150-01, AA023322, HD081437, R21AG039572]; National Institute on Aging (NIA)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Aging (NIA) [1R01AG13662-01A2]; National Institute on Drug AbuseUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Drug Abuse (NIDA) [DA011015]; Longitudinal Twin Study grant [HD10333]; MSU; National Institute of Mental Health (NIMH)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [R01MH081813, R01MH0820-54, R01MH092377-02, R21MH070542-01, R03MH63851-01]; Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) [R01HD066040]; MSU Foundation [11-SPG-2518]; NIMHUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [R01MH58354]; NIH/NIAUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Aging (NIA) [R01AG018384, R01AG018386, R01AG022381, R01AG022982]; VA San Diego Center of Excellence for Stress and Mental Health; Cooperative Studies Program of the Office of Research & Development of the US Department of Veterans Affairs (VA); Global Research Network Program of the National Research Foundation (NRF) [2011-220-E00006]; NRF of Korea [NRF-371-2011-1 B00047]; Japan Society for the Promotion of ScienceMinistry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of Science [15H05105]; National Health and Medical Research CouncilNational Health and Medical Research Council of Australia [1079102]; ERCEuropean Research Council (ERC) [240994]; [POCI/DES/56834/2004]; [5T32DA017637]; [5T32AG052371] This study was conducted within the Collaborative Project of Development of Anthropometrical Measures in Twins (Academy of Finland Grant 266592). Funding for individual collaborators is as follows. The Child and Adolescent Twin Study in Sweden is supported by the Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social and Medical Sciences Framework Grant 340-2013-5867, grants provided by the Stockholm County Council (ALF projects), the Swedish Heart-Lung Foundation, and the Swedish Asthma and Allergy Association's Research Foundation. The Netherlands Twin Register acknowledges support from the Netherlands Organization for Scientific Research and MagW/ZonMW Grants 904-61-090, 985-10-002, 912-10-020, 904-61-193,480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, and Spinozapremie-56-464-14192; Vrije University's Institute for Health and Care Research; the European Research Council (ERC; grant 230374); and the Avera Institute, Sioux Falls, South Dakota. Data collection and analyses in Finnish twin cohorts have been supported by the European Network for Genetic and Genomic Epidemiology (ENGAGE; FP7-HEALTH-F4-2007, grant agreement 201413), the National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, and AA-09203 to R. J. Rose), the Academy of Finland Center of Excellence in Complex Disease Genetics (grants 213506 and 129680), and the Academy of Finland (grants 100499, 205585, 118555, 141054, 265240, 264146, and 312073 to J. Kaprio). Since its origin, the East Flanders Prospective Survey has been partly supported by grants from the Fund of Scientific Research, Flanders and Twins, a nonprofit Association for Scientific Research in Multiple Births (Belgium). Gemini was supported by a grant from Cancer Research UK (C1418/A7974). Data collection and research stemming from the Norwegian Twin Registry are supported, in part, by the European Union's Seventh Framework Programmes ENGAGE Consortium (grant agreement HEALTH-F4-2007-201413) and Biobank Standardization and Harmonization for Research Excellence in the European Union (grant agreement HEALTH-F4-2010-261433). Madeira data come from Genetic and Environmental Influences on Physical Activity, Fitness and Health: the Madeira Family Study (project reference: POCI/DES/56834/2004, founded by the Portuguese agency for research [the Foundation for Science and Technology]). S. Y. Oncel and F. Aliev are supported by a Kirikkale University research grant (2009/43) and a Scientific and Technological Research Council of Turkey grant (114C117). K. Silventoinen is supported by Osaka University's International Joint Research Promotion Program. The Boston University Twin Project is funded by grants (R01HD068435 and R01MH062375) from the National Institutes of Health (NIH) to K. J. Saudino. The California Twin Program was supported by the California Tobacco-Related Disease Research Program (7RT-0134H, 8RT-0107H, and 6RT-0354H) and NIH (1R01ESO15150-01). The Carolina African American Twin Study of Aging was funded by a grant from the National Institute on Aging (NIA; 1R01AG13662-01A2) to K. E. Whitfield. The Colorado Twin Registry is funded by National Institute on Drug Abuse grant DA011015 and Longitudinal Twin Study grant HD10333; B. M. Huibregtse is supported by 5T32DA017637 and 5T32AG052371.; The Michigan State University (MSU) Twin Registry has been supported by MSU, as well as by grants R01MH081813, R01MH0820-54, R01MH092377-02, R21MH070542-01, and R03MH63851-01 from the National Institute of Mental Health (NIMH), grant R01HD066040 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), and grant 11-SPG-2518 from the MSU Foundation. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of NIMH, NICHD, or NIH. The University of Southern California Twin Study is funded by a grant from NIMH (R01MH58354). The Texas Twin Project is currently funded by grants AA023322 and HD081437 from NIH. The Vietnam Era Twin Study of Aging was supported by NIH/NIA grants R01AG018384, R01AG018386, R01AG022381, and R01AG022982 and, in part, with resources of the VA San Diego Center of Excellence for Stress and Mental Health. The Cooperative Studies Program of the Office of Research & Development of the US Department of Veterans Affairs (VA) has provided financial support for the development and maintenance of the Vietnam Era Twin Registry. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of NIA/NIH or VA. The National Academy of Sciences-National Research Council Twin Registry acknowledges financial support from NIH grant R21AG039572. The Korean TwinFamily Register was supported by the Global Research Network Program of the National Research Foundation (NRF; 2011-220-E00006). The South Korea Twin Registry is supported by the NRF of Korea (NRF-371-2011-1 B00047). The West Japan Twins and Higher Order Multiple Births Registry was supported by a Grant-inAid for Scientific Research (B) (15H05105) from the Japan Society for the Promotion of Science. This research was facilitated through access to Twins Research Australia, a national resource supported by a Centre of Research Excellence Grant (1079102) from the National Health and Medical Research Council. The Longitudinal Israeli Study of Twins was funded by Starting Grant 240994 from the ERC to A. Knafo-Noam.

Background Genomic analysis of the child might offer new potential to illuminate human parenting. We examined whether offspring (G2) genome-wide genotype variation (SNPs) is associated with their mother's (G1) emotional warmth and intolerance, indicating a gene-environment correlation. If this association is stronger than between G2 ' s genes and their emotional warmth and intolerance toward their own children, then this would indicate the presence of an evocative gene-environment correlation. To further understand how G1 mother's parenting has been evoked by genetically influenced characteristics of the child (G2), we examined whether child (G2) temperament partially accounted for the association between offspring genes and parental responses. Methods Participants were from the Young Finns Study. G1 mothers (N = 2,349; mean age 39 years) self-reported the emotional warmth and intolerance toward G2 in 1980 when the participants were from 3 to 18 years old. G2 participants answered the same parenting scales in 2007/2012 (N = 1,378; mean age = 38 years in 2007; 59% female) when their children were on average 11 years old. Offspring temperament traits were self-reported in 1992 (G2 age range 15-30 years). Estimation of the phenotypic variance explained by the SNPs of G2 was done by genome-wide complex trait analysis with restricted maximum likelihood (GCTA-GREML). Results Results showed that the SNPs of a child (G2) explained 22.6% of the phenotypic variance of maternal intolerance (G1; p-value = .039). G2 temperament trait negative emotionality explained only 2.4% points of this association. G2 genes did not explain G1 emotional warmth or G2 ' s own emotional warmth and intolerance. However, further analyses of a combined measure of both G1 parenting scales found genetic effects. Parent or child gender did not moderate the observed associations. Conclusions Presented genome-wide evidence is pointing to the important role a child plays in affecting and shaping his/her family environment, though the underlying mechanisms remain unclear.

Background: Genomic analysis of the child might offer new potential to illuminate human parenting. We examined whether offspring (G2) genome‐wide genotype variation (SNPs) is associated with their mother’s (G1) emotional warmth and intolerance, indicating a gene–environment correlation. If this association is stronger than between G2’s genes and their emotional warmth and intolerance toward their own children, then this would indicate the presence of an evocative gene–environment correlation. To further understand how G1 mother’s parenting has been evoked by genetically influenced characteristics of the child (G2), we examined whether child (G2) temperament partially accounted for the association between offspring genes and parental responses. Methods: Participants were from the Young Finns Study. G1 mothers (N = 2,349; mean age 39 years) self‐reported the emotional warmth and intolerance toward G2 in 1980 when the participants were from 3 to 18 years old. G2 participants answered the same parenting scales in 2007/2012 (N = 1,378; mean age = 38 years in 2007; 59% female) when their children were on average 11 years old. Offspring temperament traits were self‐reported in 1992 (G2 age range 15–30 years). Estimation of the phenotypic variance explained by the SNPs of G2 was done by genome‐wide complex trait analysis with restricted maximum likelihood (GCTA‐GREML). Results: Results showed that the SNPs of a child (G2) explained 22.6% of the phenotypic variance of maternal intolerance (G1; p‐value = 0.039). G2 temperament trait negative emotionality explained only 2.4% points of this association. G2 genes did not explain G1 emotional warmth or G2’s own emotional warmth and intolerance. However, further analyses of a combined measure of both G1 parenting scales found genetic effects. Parent or child gender did not moderate the observed associations. Conclusions: Presented genome‐wide evidence is pointing to the important role a child plays in affecting and shaping his/her family environment, though the underlying mechanisms remain unclear.

Background: The genetic architecture of birth size may differ geographically and over time. We examined differences in the genetic and environmental contributions to birth weight, length, and ponderal index (PI) across geographic-cultural regions (Europe, North-America and Australia, and East-Asia) and across birth cohorts and how gestational age modifies these effects.Methods: Data from 26 twin cohorts in 16 countries including 57613 monozygotic and dizygotic twin pairs were pooled. Genetic and environmental variations of birth size were estimated using genetic structural equation modeling.Results: The variance of birth weight and length was predominantly explained by shared environmental factors, whereas the variance of PI was explained both by shared and unique environmental factors. Genetic variance contributing to birth size was small. Adjusting for gestational age decreased the proportions of shared environmental variance and increased the propositions of unique environmental variance. Genetic variance was similar in the geographic-cultural regions, but shared environmental variance was smaller in East-Asia than in Europe and North-America and Australia. The total variance and shared environmental variance of birth length and PI were greater from the birth cohort 1990-1999 onwards compared with the birth cohorts from 1970-1979 to 1980-1989.Conclusion: The contribution of genetic factors to birth size is smaller than that of shared environmental factors, which is partly explained by gestational age. Shared environmental variances of birth length and PI were greater in the latest birth cohorts and differed also across geographic-cultural regions. Shared environmental factors are important when explaining differences in the variation of birth size globally and over time.

It is well established that boys are born heavier and longer than girls, but it remains unclear whether birth size in twins is affected by the sex of their co-twin. We conducted an individual-based pooled analysis of 21 twin cohorts in 15 countries derived from the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), including 67,850 dizygotic twin individuals. Linear regression analyses showed that boys having a co-twin sister were, on average, 31 g (95%Cl 18 to 45) heavier and 0.16 cm (95%CI 0.045 to 0.274) longer than those with a co-twin brother. In girls, birth size was not associated (5 g birth weight; 95%Cl -8 to -18 and -0.089 cm birth length; 95% CI -0.202 to 0.025) with the sex of the co-twin. Gestational age was slightly shorter in boy-boy pairs than in boy-girl and girl-girl pairs. When birth size was standardized by gestational age, the magnitude of the associations was attenuated in boys, particularly for birth weight. In conclusion, boys with a co-twin sister are heavier and longer at birth than those with a co-twin brother. However, these differences are modest and partly explained by a longer gestation in the presence of a co-twin sister. This study was conducted within the CODATwins project (Academy of Finland #266592). The Australian Twin Registry is supported by a Centre of Research Excellence (grant ID 1079102) from the National Health and Medical Research Council administered by the University of Melbourne. The Carolina African American Twin Study of Aging (CAATSA) was funded by a grant from the National Institute on Aging (grant 1RO1-AG13662-01A2) to K.E. Whitfield. The CATSS-Study is supported by the Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Swedish Heart-Lung Foundation and the Swedish Asthma and Allergy Association's Research Foundation. Since its origin the East Flanders Prospective Survey has been partly supported by grants from the Fund of Scientific Research, Flanders and Twins, a non-profit Association for Scientific Research in Multiple Births (Belgium). Data collection and analyses in Finnish twin cohorts have been supported by ENGAGE-European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, and AA-09203 to R J Rose, the Academy of Finland Center of Excellence in Complex Disease Genetics (grant numbers: 213506, 129680), and the Academy of Finland (grants 100499, 205585, 118555, 141054, 265240, 263278 and 264146 to J Kaprio). Gemini was supported by a grant from Cancer Research UK (C1418/A7974). Anthropometric measurements of the Hungarian twins were supported by Medexpert Ltd., Budapest, Hungary. Longitudinal Israeli Study of Twins was funded by the Starting Grant no. 240994 from the European Research Council (ERC) to Ariel Knafo. The Michigan State University Twin Registry has been supported by Michigan State University, as well as grants R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01 from the National Institute of Mental Health (NIMH), R01-HD066040 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD), and 11-SPG-2518 from the MSU Foundation. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIMH, the NICHD, or the National Institutes of Health. PETS was supported by grants from the Australian National Health and Medical Research Council (grant numbers 437015 and 607358 to JC, and RS), the Bonnie Babes Foundation (grant number BBF20704 to JMC), the Financial Markets Foundation for Children (grant no. 032-2007 to JMC), and by the Victorian Government's Operational Infrastructure Support Program. The Quebec Newborn Twin Study acknowledges financial support from the Fonds Quebecois de la Recherche sur la Societe et la Culture, the Fonds de la Recherche en Sante du Quebec, the Social Science and Humanities Research Council of Canada, the National Health Research Development Program, the Canadian Institutes for Health Research, Sainte-Justine Hospital's Research Center, and the Canada Research Chair Program (Michel Boivin). The Twins Early Development Study (TEDS) is supported by a program grant (G0901245) from the UK Medical Research Council and the work on obesity in TEDS is supported in part by a grant from the UK Biotechnology and Biological Sciences Research Council (31/D19086). Currently TEDS is supported by MRC grant 'MR/M021475/1'. The West Japan Twins and Higher Order Multiple Births Registry was supported by Grant-in-Aid for Scientific Research (B) (grant number 15H05105) from the Japan Society for the Promotion of Science. Netherlands Twin Register acknowledges the Netherlands Organization for Scientific Research (NWO) and MagW/ZonMW grants 904-61-090, 985-10-002, 912-10-020, 904-61-193,480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192; VU University's Institute for Health and Care Research (EMGO+); the European Research Council (ERC - 230374), the Avera Institute, Sioux Falls, South Dakota (USA).

Research into values at an early age has only started recently, although it has expanded quickly and dynamically in the past years. The purpose of this article is twofold: First, it provides an introduction to a special section that aims to help fill the gap in value development research. The special section brings together four new longitudinal and genetically informed studies of value development from the beginning of middle childhood through early adulthood. Second, this article reviews recent research from this special section and beyond, aiming to provide new directions to the field. With new methods for assessing children's values and an increased awareness of the role of values in children's and adolescents' development, the field now seems ripe for an in-depth investigation. Our review of empirical evidence shows that, as is the case with adults, children's values are organized based on compatibilities and conflicts in their underlying motivations. Values show some consistency across situations, as well as stability across time. This longitudinal stability tends to increase with age, although mean changes are also observed. These patterns of change seem to be compatible with Schwartz's (1992) theory of values (e.g., if the importance of openness to change values increases, the importance of conservation values decreases). The contributions of culture, family, peers, significant life events, and individual characteristics to values are discussed, as well as the development of values as guides for behavior.

Theories of value development often identify adolescence as the period for value formation, and cultural and familial factors as the sources for value priorities. However, recent research suggests that value priorities can be observed as early as in middle childhood, and several studies, including one on preadolescents (Knafo & Spinath, 2011), have suggested a genetic contribution to individual differences in values. In the current study, 174 pairs of monozygotic and dizygotic 7-year old Israeli twins completed the Picture-Based Value Survey for Children (PBVS–C; Doring et al., 2010). We replicated basic patterns of relations between value priorities and variables of socialisation – gender, religiosity, and socioeconomic status– that have been found in studies with adults. Most important, values of Self-transcendence, Self-enhancement, and Conservation, were found to be significantly affected by genetic factors (29%, 47% and 31% respectively), as well as non-shared environment (71%, 53% and 69% respectively). Openness to change values, in contrast, were found to be unaffected by genetic factors at this age and were influenced by shared (19%) and non-shared (81%) environment. These findings support the recent view that values are formed at earlier ages than had been assumed previously, and they further our understanding of the genetic and environmental factors involved in value formation at young ages.

Background: There is evidence that birth size is positively associated with height in later life, but it remains unclear whether this is explained by genetic factors or the intrauterine environment. Aim: To analyze the associations of birth weight, length and ponderal index with height from infancy through adulthood within mono- and dizygotic twin pairs, which provides insights into the role of genetic and environmental individual-specific factors. Methods: This study is based on the data from 28 twin cohorts in 17 countries. The pooled data included 41,852 complete twin pairs (55% monozygotic and 45% same-sex dizygotic) with information on birth weight and a total of 112,409 paired height measurements at ages ranging from 1 to 69 years. Birth length was available for 19,881 complete twin pairs, with a total of 72,692 paired height measurements. The association between birth size and later height was analyzed at both the individual and within-pair level by linear regression analyses. Results: Within twin pairs, regression coefficients showed that a 1-kg increase in birth weight and a 1-cm increase in birth length were associated with 1.14-4.25 cm and 0.18-0.90 cm taller height, respectively. The magnitude of the associations was generally greater within dizygotic than within monozygotic twin pairs, and this difference between zygosities was more pronounced for birth length. Conclusion: Both genetic and individual-specific environmental factors play a role in the association between birth size and later height from infancy to adulthood, with a larger role for genetics in the association with birth length than with birth weight. This work was supported by the Academy of Finland (grant number #266592). The Australian Twin Registry is supported by a Centre of Research Excellence (grant ID 1079102) from the National Health and Medical Research Council administered by the University of Melbourne. The Boston University Twin Project is funded by grants (#R01 HD068435 #R01 MH062375) from the National Institutes of Health to K. Saudino. The Carolina African American Twin Study of Aging (CAATSA) was funded by a grant from the National Institute on Aging (grant 1RO1-AG13662-01A2) to K. E. Whitfield. The CATSS-Study is supported by the Swedish Research Council through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Swedish Heart-Lung Foundation and the Swedish Asthma and Allergy Association's Research Foundation. Colorado Twin Registry is funded by NIDA funded center grant DA011015, & Longitudinal Twin Study HD10333; Author Huibregtse is supported by 5T32DA017637 and 5T32AG052371. Since its origin the East Flanders Prospective Survey has been partly supported by grants from the Fund of Scientific Research, Flanders and Twins, a non-profit Association for Scientific Research in Multiple Births (Belgium). Data collection and analyses in Finnish twin cohorts have been supported by ENGAGE - European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, and AA-09203 to R J Rose, the Academy of Finland Center of Excellence in Complex Disease Genetics (grant numbers: 213506, 129680), Centre of Excellence in Research on Mitochondria, Metabolism and Disease (FinMIT, grant 272376), the Academy of Finland (grants 100499, 205585, 118555, 141054, 265240, 263278 and 264146 to J Kaprio and grant 266286 and 314383 to K Pietilainen), the Finnish Diabetes Research Foundation, Novo Nordisk Foundation, Helsinki University Central Hospital and University of Helsinki. K Silventoinen is supported by Osaka University's International Joint Research Promotion Program. Gemini was supported by a grant from Cancer Research UK (C1418/A7974). Anthropometric measurements of the Hungarian twins were supported by Medexpert Ltd., Budapest, Hungary. Korean Twin-Family Register was supported by the Global Research Network Program of the National Research Foundation (NRF 2011-220-E00006). Longitudinal Israeli Study of Twins was funded by the Starting Grant no. 240994 from the European Research Council (ERC) to Ariel Knafo. The Michigan State University Twin Registry has been supported by Michigan State University, as well as grants R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01 from the National Institute of Mental Health (NIMH), R01-HD066040 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD), and 11-SPG-2518 from the MSU Foundation. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIMH, the NICHD, or the National Institutes of Health. PETS was supported by grants from the Australian National Health and Medical Research Council (grant numbers 437015 and 607358 to JC, and RS), the Bonnie Babes Foundation (grant number BBF20704 to JMC), the Financial Markets Foundation for Children (grant no. r 032-2007 to JMC), and by the Victorian Governments Operational Infrastructure Support Program. The Quebec Newborn Twin Study acknowledges financial support from the Fonds Quebecois de la Recherche sur la Societe et la Culture, the Fonds de la Recherche en Sante du Quebec, the Social Science and Humanities Research Council of Canada, the National Health Research Development Program, the Canadian Institutes for Health Research, Sainte-Justine Hospital's Research Center, and the Canada Research Chair Program (Michel Boivin). The Twins Early Development Study (TEDS) is supported by a program grant (MR/M021475/1) from the UK Medical Research Council and the work on obesity in TEDS is supported in part by a grant from the UK Biotechnology and Biological Sciences Research Council (31/D19086). The West Japan Twins and Higher Order Multiple Births Registry was supported by Grant-in-Aid for Scientific Research (B) (grant number 15H05105) from the Japan Society for the Promotion of Science. Netherlands Twin Register acknowledges the Netherlands Organization for Scientific Research (NWO) and MagW/ZonMW grants 904-61-090, 985-10-002, 912-10-020, 904-61-193, 480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192; VU University's Institute for Health and Care Research (EMGO +); the European Research Council (ERC - 230374), the Avera Institute, Sioux Falls, South Dakota (USA).

Kaprio, Jaakko/0000-0002-3716-2455; Knafo-Noam, Ariel/0000-0003-0613-1960; de Freitas, Duarte Luis/0000-0001-6642-3370; Haworth, Claire/0000-0002-8608-289X; Siribaddana, Sisira/0000-0001-5821-2557; Kyvik, Kirsten O/0000-0003-2981-0245; Aliev, Fazil/0000-0001-8357-4699; Craig, Jeffrey M/0000-0003-3979-7849; Ordonana, Juan R./0000-0001-7779-6017; Sund, Reijo/0000-0002-6268-8117; Bartels, Meike/0000-0002-9667-7555; Kandler, Christian/0000-0002-9175-235X; Fagnani, Corrado/0000-0001-5771-7772; Huibregtse, Brooke M./0000-0003-0977-7249; Montgomery, Grant W/0000-0002-4140-8139; Colodro-Conde, Lucia/0000-0002-9004-364X; Loos, Ruth J F/0000-0002-8532-5087; Busjahn, Andreas/0000-0001-9650-6919; ONCEL, Sevgi YURT/0000-0002-0990-292X; Christensen, Kaare/0000-0002-5429-5292; Martin, Nicholas/0000-0003-4069-8020; Tan, Qihua/0000-0003-3194-0030; ROMERA, JUAN FRANCISCO SANCHEZ/0000-0002-5405-6216; D'Ippolito, Cristina/0000-0001-7902-9380; Skytthe, Axel E/0000-0002-8629-4913; Tan, Qihua/0000-0003-3194-0030; Heikkila, Kauko/0000-0002-9256-8028; Duncan, Glen/0000-0001-6909-1869; Jelenkovic, Aline/0000-0002-6191-8371; Magnusson, Patrik/0000-0002-7315-7899; mangino, massimo/0000-0002-2167-7470; Medland, Sarah E/0000-0003-1382-380X; Saffery, Richard/0000-0002-9510-4181; Plomin, Robert/0000-0002-0756-3629; Harden, Kathryn/0000-0002-1557-6737; Hotopf, Matthew/0000-0002-3980-4466; McAdams, Tom/0000-0002-6825-3499; Aaltonen, Sari/0000-0002-2873-4263; Kremen, William/0000-0002-8629-5609; Pahlen, Shandell/0000-0003-0753-4155; Llewellyn, Clare/0000-0002-0066-2827; Franz, Carol/0000-0002-8987-1755; Derom, Catherine/0000-0001-5574-796X; Willemsen, Gonneke/0000-0003-3755-0236; Rasmussen, Finn/0000-0001-7915-7809; Rebato, Esther/0000-0003-1221-8501; lee, kayoung/0000-0002-2816-554X; Sodemann, Morten/0000-0001-8992-2500; Gatz, Margaret/0000-0002-1071-9970; Boivin, Michel/0000-0001-8621-9844; Silventoinen, Karri/0000-0003-1759-3079 WOS: 000358874400002 PubMed: 26014041 For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m(2)) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes. National Institute of Mental HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute of Mental Health (NIMH) [R01 MH58354]; National Institute on AgingUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Aging (NIA) [1RO1-AG13662-01A2]; National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R21 AG039572]; WT Grant Foundation; University of London Central Research fund; Medical Research CouncilMedical Research Council UK (MRC) [G81/343, G120/635]; Economic and Social Research CouncilEconomic & Social Research Council (ESRC) [RES-000-22-2206]; Institute of Social Psychiatry [06/07-11]; Leverhulme Research FellowshipLeverhulme Trust [RF/2/RFG/2008/0145]; Goldsmiths; University of London; National Research Foundation of KoreaNational Research Foundation of Korea [NRF-371-2011-1B00047]; Danish Agency for Science, Technology and Innovation; Research Council for Health and Disease; Velux Foundation; US National Institute of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [P01 AG08761]; Fund of Scientific Research, FlandersFWO; Twins, a non-profit Association for Scientific Research in Multiple Births (Belgium); Global Research Network Program of the National Research Foundation [NRF 2011-220-E00006]; NIDAUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Drug Abuse (NIDA) [DA011015]; Longitudinal Twin Study [HD10333]; National Institute of Health grantsUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [NIA R01 AG018384, R01 AG018386, R01 AG022381, R01 AG022982]; Cooperative Studies Program of the Office of Research AMP; Development of the United States Department of Veterans Affairs; Centre of Research Excellence from the National Health and Medical Research CouncilNational Health and Medical Research Council of Australia [1079102]; Michigan State University from the National Institute of Mental Health (NIMH) [R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01]; Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD) [R01-HD066040]; MSU Foundation [11-SPG-2518]; California Tobacco-Related Disease Research ProgramUniversity of California System [7RT-0134H, 8RT-0107H, 6RT-0354H]; The National Institutes of HealthUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [1R01ESO15150-01]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China [81125007]; Australian National Health and Medical Research CouncilNational Health and Medical Research Council of Australia [437015, 607358]; Bonnie Babes Foundation [BBF20704]; Financial Markets Foundation for Children [032-2007]; Victorian Government's Operational Infrastructure Support Program; ENGAGE-European Network for Genetic and Genomic Epidemiology [201413]; National Institute of Alcohol Abuse and AlcoholismUnited States Department of Health & Human ServicesNational Institutes of Health (NIH) - USANIH National Institute on Alcohol Abuse & Alcoholism (NIAAA) [AA-12502, AA-00145, AA-09203]; Academy of Finland Center of Excellence in Complex Disease GeneticsAcademy of Finland [213506, 129680]; Academy of FinlandAcademy of Finland [100499, 205585, 118555, 141054, 265240, 263278, 264146]; Osaka University's International Joint Research Promotion Program; Kirikkale University Research Grant: KKUKirikkale University; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [114C117]; European Research Council (ERC)European Research Council (ERC) [240994]; European Union's Seventh Framework Programmes ENGAGE ConsortiumEuropean Union (EU) [HEALTH-F4-2007-201413]; BioSHaRE EU [HEALTH-F4-2010-261433]; Seneca FoundationFundacion Seneca; Regional Agency for Science and Technology, Murcia, Spain [08633/PHCS/08, 15302/PHCS/10]; Ministry of Science and Innovation, SpainSpanish Government [PSI11560-2009]; UK Medical Research CouncilMedical Research Council UK (MRC) [G0901245]; UK Biotechnology and Biological Sciences Research CouncilBiotechnology and Biological Sciences Research Council (BBSRC) [31/D19086]; Portuguese agency for research (The Foundation for Science and Technology) [POCI/DES/56834/2004]; National Institutes of Health.United States Department of Health & Human ServicesNational Institutes of Health (NIH) - USA [R01 HD068435, R01 MH062375]; Wellcome TrustWellcome Trust; European Community's Seventh Framework ProgrammeEuropean Union (EU); National Institute for Health Research (NIHR) BioResource Clinical Research Facility and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London; Netherlands Organization for Scientific Research (NWO)Netherlands Organization for Scientific Research (NWO); MagW/ZonMW [904-61-090, 985-10-002, 912-10-020, 904-61-193, 480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192]; VU University's Institute for Health and Care Research (EMGO+); European Research CouncilEuropean Research Council (ERC) [ERC-230374]; Avera Institute, Sioux Falls, South Dakota (USA); Cancer Research UKCancer Research UK [C1418/A7974]; [5T32DA017637-10]; [NIH RC2 HL103416]; Cancer Research UKCancer Research UK [14133]; Medical Research CouncilMedical Research Council UK (MRC) [G0901245, MC_UU_12013/1]; NNF Center for Basic Metabolic ResearchNovo Nordisk Foundation [Metabolic Genetics]; Novo Nordisk FondenNovo NordiskNovo Nordisk Foundation [NNF10CC1016515] This study was conducted within the CODATwins project (Academy of Finland #266592). Support for participating twin projects: the University of Southern California Twin Study is funded by a grant from the National Institute of Mental Health (R01 MH58354). The Carolina African American Twin Study of Aging (CAATSA) was funded by a grant from the National Institute on Aging (grant 1RO1-AG13662-01A2) to K. E. Whitfield. The NAS-NRC Twin Registry acknowledges financial support from the National Institutes of Health grant number R21 AG039572. Waves 1-3 of Genesis 12-19 were funded by the WT Grant Foundation, the University of London Central Research fund and a Medical Research Council Training Fellowship (G81/343) and Career Development Award (G120/635) to Thalia C. Eley. Wave 4 was supported by grants from the Economic and Social Research Council (RES-000-22-2206) and the Institute of Social Psychiatry (06/07-11) to Alice M. Gregory who was also supported at that time by a Leverhulme Research Fellowship (RF/2/RFG/2008/0145). Wave 5 was supported by funding to Alice M. Gregory from Goldsmiths, University of London. Anthropometric measurements of the Hungarian twins were supported by Medexpert Ltd., Budapest, Hungary. South Korea Twin Registry is supported by National Research Foundation of Korea (NRF-371-2011-1B00047). The Danish Twin Registry is supported by the National Program for Research Infrastructure 2007 from the Danish Agency for Science, Technology and Innovation, The Research Council for Health and Disease, the Velux Foundation and the US National Institute of Health (P01 AG08761). Since its origin, the East Flanders Prospective Survey has been partly supported by grants from the Fund of Scientific Research, Flanders and Twins, a non-profit Association for Scientific Research in Multiple Births (Belgium). Korean Twin-Family Register was supported by the Global Research Network Program of the National Research Foundation (NRF 2011-220-E00006). The Colorado Twin Registry is funded by NIDA funded center grant DA011015 and Longitudinal Twin Study HD10333; Author Huibregtse is supported by 5T32DA017637-10. The Vietnam Era Twin Study of Aging was supported by National Institute of Health grants NIA R01 AG018384, R01 AG018386, R01 AG022381, and R01 AG022982, and, in part, with resources of the VA San Diego Center of Excellence for Stress and Mental Health. The Cooperative Studies Program of the Office of Research & Development of the United States Department of Veterans Affairs has provided financial support for the development and maintenance of the Vietnam Era Twin (VET) Registry. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIA/NIH, or the VA. The Australian Twin Registry is supported by a Centre of Research Excellence (grant ID 1079102) from the National Health and Medical Research Council administered by the University of Melbourne. The Michigan State University Twin Registry has been supported by Michigan State University, as well as grants R01-MH081813, R01-MH0820-54, R01-MH092377-02, R21-MH070542-01, R03-MH63851-01 from the National Institute of Mental Health (NIMH), R01-HD066040 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD), and 11-SPG-2518 from the MSU Foundation. The content of this manuscript is solely the responsibility of the authors and does not necessarily represent the official views of the NIMH, the NICHD, or the National Institutes of Health.; r The California Twin Program was supported by The California Tobacco-Related Disease Research Program (7RT-0134H, 8RT-0107H, 6RT-0354H) and the National Institutes of Health (1R01ESO15150-01). The Guangzhou Twin Eye Study is supported by National Natural Science Foundation of China (grant #81125007). PETS was supported by grants from the Australian National Health and Medical Research Council (grant numbers 437015 and 607358 to JC, and RS), the Bonnie Babes Foundation (grant number BBF20704 to JMC), the Financial Markets Foundation for Children (grant no. 032-2007 to JMC), and by the Victorian Government's Operational Infrastructure Support Program. Data collection and analyses in Finnish twin cohorts have been supported by ENGAGE-European Network for Genetic and Genomic Epidemiology, FP7-HEALTH-F4-2007, grant agreement number 201413, National Institute of Alcohol Abuse and Alcoholism (grants AA-12502, AA-00145, and AA-09203 to R. J. Rose, the Academy of Finland Center of Excellence in Complex Disease Genetics (grant numbers: 213506, 129680), and the Academy of Finland (grants 100499, 205585, 118555, 141054, 265240, 263278 and 264146 to J. Kaprio). K. Silventoinen is supported by Osaka University's International Joint Research Promotion Program. S. Y. Oncel and F. Aliev are supported by Kirikkale University Research Grant: KKU, 2009/43 and TUBITAK grant 114C117. The Longitudinal Israeli Study of Twins was funded by the Starting Grant no. 240994 from the European Research Council (ERC) to Ariel Knafo. Data collection and research stemming from the Norwegian Twin Registry is supported, in part, from the European Union's Seventh Framework Programmes ENGAGE Consortium (grant agreement HEALTH-F4-2007-201413, and BioSHaRE EU (grant agreement HEALTH-F4-2010-261433). The Murcia Twin Registry is supported by the Seneca Foundation, Regional Agency for Science and Technology, Murcia, Spain (08633/PHCS/08 & 15302/PHCS/10) and Ministry of Science and Innovation, Spain (PSI11560-2009). The Twins Early Development Study (TEDS) is supported by a program grant (G0901245) from the UK Medical Research Council and the work on obesity in TEDS is supported in part by a grant from the UK Biotechnology and Biological Sciences Research Council (31/D19086). The Madeira data comes from the following project: genetic and environmental influences on physical activity, fitness, and health: the Madeira family study Project reference: POCI/DES/56834/2004 founded by the Portuguese agency for research (The Foundation for Science and Technology). The Boston University Twin Project is funded by grants (#R01 HD068435 #R01 MH062375) from the National Institutes of Health to K. Saudino. TwinsUK was funded by the Wellcome Trust; European Community's Seventh Framework Programme (FP7/2007-2013). The study also receives support from the National Institute for Health Research (NIHR) BioResource Clinical Research Facility and Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London. The University of Washington Twin Registry is supported by the grant NIH RC2 HL103416 (D. Buchwald, PI). The Netherlands Twin Register acknowledges the Netherlands Organization for Scientific Research (NWO) and MagW/ZonMW grants 904-61-090, 985-10-002, 912-10-020, 904-61-193,480-04-004, 463-06-001, 451-04-034, 400-05-717, Addiction-31160008, Middelgroot-911-09-032, Spinozapremie 56-464-14192; VU University's Institute for Health and Care Research (EMGO+); the European Research Council (ERC-230374), the Avera Institute, Sioux Falls, South Dakota (USA).; r Gemini was supported by a grant from Cancer Research UK (C1418/A7974).