THE CORRELATION BETWEEN g LOADINGS AND HERITABILITY IN RUSSIA.

The study focused on the extent to which the general factor of intelligence g and heritability coefficients of the subtests of an IQ battery correlate. Modest to strong positive correlations were found in five studies from Western countries and six studies from a Japanese meta-analysis. The results for Russian twins were compared with those of the Western and Japanese studies. Data from 402 twins aged 13 and 296 twins aged 16 showed correlations of r=-0.45 and r=-0.60, respectively. It is concluded that the two data points are clearly not in line with established findings. It may be that the link between g loadings and heritabilities is more complex than previously thought.

Reciprocal Effects Between Negative Parenting and Children's Callous-Unemotional Traits From Mid to Late Childhood.

OBJECTIVE: The role of negative parenting in the development of callous-unemotional (CU) traits remains unclear. Both negative parenting and CU traits are influenced by genetic and environmental factors. The authors used genetically informed longitudinal cross-lagged models to examine the extent to which reciprocal effects between negative parenting and children's CU traits in mid-to-late childhood are genetic versus environmental in origin. METHODS: In 9,260 twin pairs from the Twins Early Development Study, the authors estimated cross-lagged effects between negative parenting (discipline and feelings) and children's CU traits in mid (ages 7-9) and late (ages 9-12) childhood. RESULTS: CU traits were strongly heritable and stable. Stability was explained largely by genetic factors. The influence of negative parenting on the development of CU traits was small and driven mostly by genetic and shared environmental factors. In mid childhood, the influence of children's CU traits on subsequent negative parenting (i.e., evoked by children's CU traits) was also small and mostly genetic in origin. In late childhood, CU traits showed no effects on negative parental discipline and small effects on negative parental feelings, which reflected mostly shared environmental factors. CONCLUSIONS: In mid-to-late childhood, genetic factors strongly influenced the development of CU traits, whereas environmental effects of negative parenting were small. Negative parenting was also relatively unaffected by CU traits. The small reciprocal effects originated mostly from genetic and shared environmental factors. Therefore, repeated intensive interventions addressing multiple risk factors rather than negative parenting alone may be best positioned to support families of children with CU traits across development.

Intergenerational transmission of genetic risk for hyperactivity and inattention. Direct genetic transmission or genetic nurture?

Background: Hyperactivity and inattention, the symptoms of ADHD, are marked by high levels of heritability and intergenerational transmission. Two distinct pathways of genetic intergenerational transmission are distinguished: direct genetic transmission when parental genetic variants are passed to the child's genome and genetic nurture when the parental genetic background contributes to the child's outcomes through rearing environment. This study assessed genetic contributions to hyperactivity and inattention in childhood through these transmission pathways. Methods: The sample included 415 families from the Quebec Newborn Twin Study. Twins' hyperactivity and inattention were assessed in early childhood by parents and in primary school by teachers. The polygenic scores for ADHD (ADHD-PGS) and educational attainment (EA-PGS) were computed from twins' and parents' genotypes. A model of intergenerational transmission was developed to estimate (1) the contributions of parents' and children's PGS to the twins' ADHD symptoms and (2) whether these variances were explained by genetic transmission and/or genetic nurture. Results: ADHD-PGS explained up to 1.6% of the variance of hyperactivity and inattention in early childhood and primary school. EA-PGS predicted ADHD symptoms at both ages, explaining up to 1.6% of the variance in early childhood and up to 5.5% in primary school. Genetic transmission was the only significant transmission pathway of both PGS. The genetic nurture channeled through EA-PGS explained up to 3.2% of the variance of inattention in primary school but this association was non-significant. Conclusions: Genetic propensities to ADHD and education predicted ADHD symptoms in childhood, especially in primary school. Its intergenerational transmission was driven primarily by genetic variants passed to the child, rather than by environmentally mediated parental genetic effects. The model developed in this study can be leveraged in future research to investigate genetic transmission and genetic nurture while accounting for parental assortative mating.

Literacy and numeracy are more heritable than intelligence in primary school.

Because literacy and numeracy are the focus of teaching in schools, whereas general cognitive ability (g, intelligence) is not, it would be reasonable to expect that literacy and numeracy are less heritable than g. Here, we directly compare heritabilities of multiple measures of literacy, numeracy, and g in a United Kingdom sample of 7,500 pairs of twins assessed longitudinally at ages 7, 9, and 12. We show that differences between children are significantly and substantially more heritable for literacy and numeracy than for g at ages 7 and 9, but not 12. We suggest that the reason for this counterintuitive result is that universal education in the early school years reduces environmental disparities so that individual differences that remain are to a greater extent due to genetic differences. In contrast, the heritability of g increases during development as individuals select and create their own environments correlated with their genetic propensities.

The Place of Gender Stereotypes in the Network of Cognitive Abilities, Self-Perceived Ability and Intrinsic Value of School in School Children Depending on Sex and Preferences in STEM.

Adolescents face many barriers on the path towards a STEM profession, especially girls. We examine the gender stereotypes, cognitive abilities, self-perceived ability and intrinsic values of 546 Russian school children from 12 to 17 years old by sex and STEM preferences. In our sample, STEM students compared to no-STEM have higher cognitive abilities, intrinsic motivation towards math and science, are more confident in their math abilities and perceive math as being easier. Boys scored higher in science, math and overall academic self-efficacy, intrinsic learning motivation and math's importance for future careers. Meanwhile, girls displayed higher levels of gender stereotypes related to STEM and lower self-efficacy in math. A network analysis was conducted to identify the structure of psychological traits and the position of the stem-related stereotypes among them. The analysis arrived at substantially different results when adolescents were grouped by sex or preference towards STEM. It also demonstrated that gender stereotypes are connected with cognitive abilities, with a stronger link in the no-STEM group. Such stereotypes play a more important role for girls than boys and, jointly with the general self-efficacy of cognitive and academic abilities, are associated with the factors that distinguish groups of adolescents in their future careers.

Reading self-perceived ability, enjoyment and achievement: A genetically informative study of their reciprocal links over time.

Extant literature has established a consistent association between aspects of reading motivation, such as enjoyment and self-perceived ability, and reading achievement, in that more motivated readers are generally more skilled readers. However, the developmental etiology of this relation is yet to be investigated. The present study explores the development of the motivation-achievement association and its genetic and environmental underpinnings. Applying cross-lagged design in a sample of 13,825 twins, we examined the relative contribution of genetic and environmental factors to the association between reading enjoyment and self-perceived ability and reading achievement. Children completed a reading comprehension task and self-reported their reading enjoyment and perceived ability twice in middle childhood: when they were 9-10 and 12 years old. Results showed a modest reciprocal association over time between reading motivation (enjoyment and perceived ability) and reading achievement. Reading motivation at age 9-10 statistically predicted the development of later achievement, and similarly, reading achievement at age 9-10 predicted the development of later motivation. This reciprocal association was observed beyond the stability of the variables and their contemporaneous correlation and was largely explained by genetic factors. (PsycINFO Database Record