Behavioral Genetic Approaches and Family Theory

Family interactions in toddlerhood influence social competence in preschool age: Accounting for genetic and prenatal influences

Identification of early promotive and risk factors for social competence is important for fostering children's successful social development; particularly given social competence is essential for children's later academic and psychological well-being. While research suggests that the early parent-child relationship, genetics, and prenatal influences are associated with social competence, there is less research considering how these factors may operate together to shape children's social competence in early childhood. Using a genetically informed sample from the Early Growth and Development Study (N = 561), we examined multiple levels of influence (i.e., genetic, prenatal, parenting, and child characteristics) on children's social competence at 4.5 years old. Results from structural equation models showed adoptive mother overreactivity at 18 months was positively associated with child dysregulation at 27 months, which, in turn, was associated with lower levels of social competence at 4.5 years. Also, child reactivity at 18 months was independently associated with higher levels of adoptive mother overreactivity at 27 months, which, in turn, was associated with lower levels of social competence at 4.5 years. Finally, we found an evocative effect on adoptive fathers' overreactivity at 18 months such that prenatal birth mother distress was negatively associated with adoptive fathers' overreactivity at 18 months. Overall, this study found evidence for genetic influences, and bidirectional associations between parent and child in toddlerhood that are related to lower levels of social competence when children were 4.5 years old. We also found that the prenatal environment was associated with parenting, but not with child behavior directly. This study's ability to simultaneously examine multiple domains of influence helps provide a more comprehensive picture of important mechanisms and developmental periods for children's early social competence.

The intergenerational transmission of mathematics achievement in middle childhood: A prospective adoption design

The present study uses a parent-offspring adoption design to examine the dual roles of heritable and environmental influences on children's mathematics achievement. Linked sets (N = 195) of adopted children, adoptive parents, and birth parents each completed a measure of mathematics fluency (i.e., simple computational operations). Birth parent mathematics achievement and adoptive father mathematics achievement positively correlated with child achievement scores at age 7, whereas adoptive mother and adopted child mathematics achievement scores were not significantly associated with one another. Additionally, findings demonstrated no significant effects of gene-environment interactions on child mathematics achievement at age 7. These results indicate that both heritable and rearing environmental factors contribute to children's mathematics achievement and identify unique influences of the paternal rearing environment on mathematics achievement in middle childhood.

Genetic influences on musical specialization: a twin study on choice of instrument and music genre

Though several studies show that genetic factors influence individual differences in musical engagement, aptitude, and achievement, no study to date has investigated whether specialization among musically active individuals in terms of choice of instrument and genre is heritable. Using a large twin cohort, we explored whether individual differences in instrument choice, instrument category, and the type of music individuals engage in can entirely be explained by the environment or are partly due to genetic influences. About 10,000 Swedish twins answered an extensive questionnaire about music-related traits, including information on the instrument and genre they played. Of those, 1259 same-sex twin pairs reported to either play an instrument or sing. We calculated the odds ratios (ORs) for concordance in music choices (if both twins played) comparing identical and nonidentical twin pairs, with significant ORs indicating that identical twins are more likely to engage in the same type of music-related behavior than are nonidentical twins. The results showed that for almost all music-related variables, the odds were significantly higher for identical twins to play the same musical instrument or music genre, suggesting significant genetic influences on such music specialization. Possible interpretations and implications of the findings are discussed.