This essay is focused on the research into the genetic etiology of creativity and related processes. In an attempt to identify the most salient points of this research, the article provides a brief overview of quantitative-genetic (family and twin) and molecular-genetic (candidate-gene and whole-genome) studies of creativity. To conclude, the…

Given the importance of writing for academic achievement, this study aimed to understand how early oral language contributes to later writing skills. The first objective was to determine if preschool language skills were associated with high school writing, and if so, whether they contributed directly or indirectly through school age language. The…

Symptoms of anxiety and depression are commonly comorbid and partially share a genetic etiology. Mean levels of anxiety and depression increase over the transition to adolescence, particularly in girls, suggesting a possible role of pubertal development in the activation of underlying genetic risks. The current study examined how genetic and…

Purpose: Oxytocin and arginine vasopressin are associated with different aspects of the stress response. As stress is regarded as a risk factor for vocal symptoms, we wanted to explore the association between the oxytocin receptor gene ("OXTR") and arginine vasopressin 1A receptor gene ("AVPR1A") single-nucleotide polymorphisms…

We investigated the double-deficit hypothesis (DDH) in samples of U.S. (N = 489), Australian (N = 264), and Scandinavian (N = 293) children followed from preschool to grade 2. Children were assigned to double deficit, single deficit and no deficit subtypes in preschool, kindergarten, and grade 1 and compared on reading and spelling in grades 1 and…

Childhood gender nonconformity (femininity in males, masculinity in females) predicts a nonstraight (gay, lesbian, or bisexual) sexual orientation in adulthood. In previous work, nonstraight twins reported more childhood gender nonconformity than their genetically identical, but straight, cotwins. However, self-reports could be biased. We…

Both genes and the environment are important for individual differences in expertise, but little is known about gene-environment interactions underlying domain-specific achievement. Here we explored this issue in a large Swedish twin cohort (N = 6,610), using moderator modeling with musical expertise as a model domain. Specifically, we tested…

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…

Most study samples show less variability in key variables than do their source populations due most often to indirect selection into study participation associated with a wide range of personal and circumstantial characteristics. Formulas exist to correct the distortions of population-level correlations created. Formula accuracy has been tested…

We examined whether attained socioeconomic status (SES) moderated genetic and environmental sources of individual differences in cognitive performance using pooled data from 9 adult twin studies. Prior work concerning SES moderation of cognitive performance has focused on rearing SES. The current adult sample of 12,196 individuals (aged 27-98…

Purpose: This review article summarizes a program of longitudinal investigation of twins' language acquisition with a focus on causal pathways for specific language impairment (SLI) and nonspecific language impairment in children at 4 and 6 years with known history at 2 years. Method: The context of the overview is established by legacy scientific…

Asbury and Wai ("Journal of School Choice," 2019) perform a valuable service by summarizing much available behavior--genetic research on academic achievement. However they consider that no specific policies stem from the research body at this time. Here we do propose a policy based on some of our research using twins, namely that…

Children's lexical processing speed at 18 to 25 months of age has been linked to concurrent and later language abilities. In the current study, we extend this finding to children aged 36 months. Children (N = 126) participated in a lexical processing task in which they viewed two static images on noun trials (e.g., an ear of corn and a hat), or…

Purpose: We investigated whether participants who reported more often occurring vocal symptoms showed higher salivary cortisol levels and if such possible associations were different for men and women. Method: The participants (N = 170; men n = 49, women n = 121) consisted of a population-based sample of Finnish twins born between 1961 and 1989.…

Children's negative emotionality (NE) is frequently associated with parental negativity, but causal understanding of this relationship is limited. In addition, little is known about how genetic and environmental factors affect this relationship during middle childhood. We addressed these gaps by applying a quantitative genetic analysis to…