Previous studies have found correlations between parent input and child language outcomes, providing prima facie evidence for a causal relation. However, this could also reflect the effects of shared genes. The present study removed this genetic confound by measuring English vocabulary growth in 29 preschool-aged children (21 girls) aged…

Parenting and children's temperament are important influences on language development. However, temperament may reflect prior parenting, and parenting effects may reflect genes common to parents and children. In 561 U.S. adoptees (57% male) and their birth and rearing parents (70% and 92% White, 13% and 4% African American, and 7% and 2% Latinx,…

This study examined gene-environment correlation (rGE) in intellectual and academic development in 561 U.S.-based adoptees (57% male; 56% non-Latinx White, 19% multiracial, 13% Black or African American, 11% Latinx) and their birth and adoptive parents between 2003 and 2017. Birth mother intellectual and academic performance predicted adoptive…

Intellectual performance is highly heritable and robustly predicts lifelong health and success but the earliest manifestations of genetic effects on this asset are not well understood. This study examined whether early executive function (EF) or verbal performance mediate genetic influences on subsequent intellectual performance, in 561 U.S.-based…

Children adopted from institutions have been studied as models of the impact of stimulus deprivation on cognitive development (Nelson, Bos, Gunnar, & Sonuga-Barke, 2011), but these children may also suffer from micronutrient deficiencies (Fuglestad et al., 2008). The contributions of iron deficiency (ID) and duration of deprivation on…

This investigation examined the mutual influences between structured parenting and child social wariness during toddlerhood using a longitudinal adoption design. The sample consisted of 361 adoption-linked families, each including an adopted child, adoptive parents, and a birth mother. Heightened social wariness in children at age 18 months…

Findings are presented on a U.K. study of 41 gay father families, 40 lesbian mother families, and 49 heterosexual parent families with an adopted child aged 3-9 years. Standardized interview and observational and questionnaire measures of parental well-being, quality of parent-child relationships, child adjustment, and child sex-typed behavior…

Coparenting is associated with child behavior in families with heterosexual parents, but less is known about coparenting among lesbian- and gay-parent families. Associations were studied among self-reported divisions of labor, coparenting observations, and child adjustment ("M[subscript age]" = 3 years) among 104 adoptive families headed…

The current longitudinal study examined trajectories of child negative emotionality, parenting efficacy, and overreactive parenting among 382 adoptive families during infancy and toddlerhood. Data were collected from adoptive parents when the children were 9-, 18-, and 27-month-old. Latent growth curve modeling indicated age-related increases in…

This study examined the longitudinal association between marital instability and child sleep problems at ages 9 and 18 months in 357 families with a genetically unrelated infant adopted at birth. This design eliminates shared genes as an explanation for similarities between parent and child. Structural equation modeling indicated that T1 marital…

The French language development of children adopted (n = 24) from China was compared with that of control children matched for socioeconomic status, sex, and age. The children were assessed at 50 months of age, on average, and 16 months later. The initial assessment revealed that the 2 groups did not differ with respect to socioemotional…

To further the understanding of the effects of early experiences, 9-month-old infants were observed during a frustration task. The analytical sample was composed of 348 linked triads of participants (adoptive parents, adopted child, and birth parent[s]) from a prospective adoption study. It was hypothesized that genetic risk for externalizing…

Intelligence test scores were obtained from parents and children in 300 adoptive families and compared with similar data available from the children's biological mothers. Results support the hypothesis that genetic variability is an important influence in the development of individual differences in intelligence. (Author/RH)

Investigates developmental changes in adopted and nonadopted children's knowledge of adoption. A total of 200 children ranging in age from 4 to 13 years participated. Results indicated clear developmental trends in children's knowledge of the nature of the adoptive family relationship, as well as in their understanding of the motivational basis…

No differences were found in mother-infant attachment between nonadopted and intraracial adopted subjects or between intraracial and interracial adopted subjects. Suggests that the higher incidence of psychological problems found among adoptees in middle childhood and adolescence cannot be explained in terms of insecure attachment relationships…