Purpose: The extant literature suggests that individual differences in speech perception can be linked to broad receptive language phenotype. For example, a recent study found that individuals with a smaller receptive vocabulary showed diminished lexically guided perceptual learning compared to individuals with a larger receptive vocabulary. Here,…

There is considerable variability in the extent to which young people with developmental language disorder (DLD) experience mental health difficulties. What drives these individual differences remains unclear. In the current article, data from the Twin Early Development Study were used to investigate the genetic and environmental influences on…

Background: Despite a large body of research that has explored the influence of genetic and environmental factors on educationally relevant traits, few studies have explored teachers' beliefs about, or knowledge of, developments in behavioural genetics related to education. Aims: This study aimed to describe the beliefs and knowledge of UK…

According to models of differential susceptibility, the same neurobiological and temperamental traits that determine increased sensitivity to stress and adversity also confer enhanced responsivity to the positive aspects of the environment. Differential susceptibility models have expanded to include complex developmental processes in which genetic…

This study examined individual differences in ADHD symptoms and executive function (EF) in children with Down syndrome (DS) in relation to the dopamine receptor D4 (DRD4) gene, a gene often linked to ADHD in people without DS. Participants included 68 individuals with DS (7-21 years), assessed through laboratory tasks, caregiver reports, and…

Most of the individual difference variance in the population is found "within" families, yet studying the processes causing this variation is difficult due to confounds between genetic and nongenetic influences. Quasi-experiments can be used to test hypotheses regarding environment exposure (e.g., timing, duration) while controlling for…

Autism is a pervasive developmental condition with complex aetiology. To aid the discovery of genetic mechanisms, researchers have turned towards identifying potential endophenotypes--subtle neurobiological or neurocognitive traits present in individuals with autism and their "unaffected" relatives. Previous research has shown that relatives of…

Does the choice of test for assessing reading comprehension influence the outcome of genetic analyses? A twin design compared two types of reading comprehension tests classified as primarily associated with word decoding (RC-D) or listening comprehension (RC-LC). For both types of tests, the overall genetic influence is high and nearly identical.…

Recent psychological and neuropsychological research suggests that executive functions--the cognitive control processes that regulate thought and action--are multifaceted and that different types of executive functions are correlated but separable. The present multivariate twin study of 3 executive functions (inhibiting dominant responses,…

Examined influences on children's behavior problems in households defined by marital status and sibling relatedness. Found that genetic influences accounted for 81 to 94 percent of mean-level difference in behavior problems between two-parent/full sibling, and the mother-only/half sibling groups. Shared environmental influences accounted for 67 to…

Used the Sibling Inventory of Differential Experience with 396 adolescent and young adult children to determine the extent to which genetic differences between siblings or sibling differences in family constellation variables were responsible for differential experiences. (HOD)

Background: Dissociation--a pattern of general disruption in memory and consciousness--has been found to be an important cognitive component of children's and adults' coping with severe trauma. Dissociative experiences include amnesia, identity disturbance, age regression, difficulty with concentration, and trance states. Stable individual…