Transposable elements (TEs) have been implicated in autism spectrum disorder (ASD). However, our understanding of their roles is far from complete. Herein, we explored de novo TE insertions (dnTEIs) and de novo variants (DNVs) across the genomes of dizygotic twins with ASD and their parents. The neuronal regulatory elements had a tendency to…

Purpose: The aim of this study is to establish which specific cognitive abilities are phenotypically related to reading skill in adolescence and determine whether this phenotypic correlation is explained by polygenetic overlap. Method: In an Australian population sample of twins and non-twin siblings of European ancestry (734 [less than or equal…

Executive functions (EFs) and intelligence (IQ) are phenotypically correlated. In twin studies, latent variables for EFs and IQ display moderate to high heritability estimates; however, they show variable genetic correlations in twin studies spanning childhood to middle age. We analyzed data from over 11,000 children (9- to 10-year-olds, including…

Estimates of shared environmental influence on educational attainment (EA) using the Classical Twin Design (CTD) have been enlisted as genetically sensitive measures of unequal opportunity. However, key assumptions of the CTD appear violated for EA. In this study we compared CTD estimates of shared environmental influence on EA with estimates from…

Prior theoretical and empirical research has highlighted links between positive parenting and the socioeconomic characteristics of the family's neighborhood, but has yet to illuminate the etiologic origins of this association. One possibility is that the various predictors of parenting outlined by Belsky (1984; e.g., characteristics of the child,…

Parenting behaviors have long been recognized as crucial to children's healthy development. However, examinations of the etiology of these behaviors are less prevalent. The current study investigated the driving forces behind parental warmth and discipline, particularly whether they are related more to traits within the parent or reactions to…

The ability to perceive approximate numerosity is present in many animal species, and emerges early in human infants. Later in life, it is moderately heritable and associated with mathematical abilities, but the etiology of the Approximate Number System (ANS) and its degree of independence from other cognitive abilities in infancy is unknown.…

Twins regularly score nearly a standard deviation below the population mean on standardized measures of cognitive development in infancy but recover to the population mean by early childhood, making rapid gains through the toddler years. To date, only polynomial growth models have been fit to model cognitive recovery across childhood, limiting the…

The current analysis investigates genetic and environmental influences on the bidirectional relationships between temperament and general cognitive ability (GCA). Measures of GCA and three temperament factors (persistence, approach, and reactivity) were collected from 486 children ages 4-9 years (80% white, 50% female) from the Louisville Twin…

Dysregulation of biological stress response, as measured by cortisol output, has been a primary candidate mechanism for how social experiences become biologically embedded. Cortisol is the primary output of the hypothalamic pituitary adrenal (HPA) axis. Cortisol levels vary systematically across the day and change in response to both sudden, acute…

We compared dyad-focused maternal speech (protoconversations and maternal speech describing the dyad) in interactions of mothers with their twin and singleton infants. Nine twins and nine singletons, coming from urban areas of Crete (Greece), were video-recorded at home in spontaneous face-to-face interactions with their mothers, from the 2nd to…

Future orientation tends to prevent engagement in risk behaviours and results in good academic performance among adolescents. Our study aimed to establish whether genetic factors contributed to future orientation among Chinese adolescents. We recruited 988 pairs of twins from Beijing. By constructing a high-order A (additive genetic variance) C…

Background: Children's academic achievement is considerably influenced by genetic factors, which rarely operate independently of environmental influences such as teachers' behaviour. Praise and punitive discipline are commonly used management strategies by teachers. However, their effects on the genetic expression of children's academic…

This study investigated the association between autism and self-reported eating problems and the influence of gender on the association, in a sample of adolescent and adult twins (N = 192). Autistic traits and autism diagnosis were associated with both total and specific eating problems, including selective eating and sensory sensitivity during…

Background: Educational attainment is connected to many important life outcomes, and the previous research has already focused on identifying its genetic and environmental components. However, most of these studies used twin data only and did not incorporate information from other family members. Twin studies typically decompose the phenotypic…