The broader autism phenotype (BAP) is a term applied to individuals with personality and cognitive traits that are similar to but milder than those observed in autism spectrum disorder (ASD). Subtle autistic traits in the core diagnostic domains of social communication and rigid behavior were described in family members of people with an ASD even…

Effortful control, or the ability to suppress a dominant response to perform a subdominant response, is an early-emerging temperament trait that is linked with positive social-emotional development. Fragile X syndrome (FXS) is a single-gene disorder characterized by hallmark regulatory impairments, suggesting diminished effortful control. This…

Individuals with sex chromosome trisomies (SCTs) have an increased risk of language delays and impairments. However, there are only a few data relative to their language development in early childhood. The present study aimed to investigate the preverbal skills shown by a group of 8-month-old children with SCTs to assess the presence of a possible…

Background: Evocative gene-environment correlation (rGE) describes a process through which children's heritable characteristics influence their rearing environments. The current study examined if heritable influences on parenting and children's behavioral outcomes operate through child negative emotionality. Method: Using data from the Early…

Autism spectrum disorder (ASD) and autism-like traits are associated with deficits in face memory ability, although it is not yet clear whether this deficit reflects a specific aspect of the ASD/autism-like phenotype. We addressed this issue using a neurotypical sample of adolescent twins (N[subscript complete pairs] = 782) drawn from the Twins…

This study examined the developmental profile of male infants with fragile X syndrome (FXS) and its divergence from typical development and development of infants at high risk for autism associated with familial recurrence (ASIBs). Participants included 174 boys ranging in age from 5 to 28 months. Cross-sectional profiles on the Mullen Scales of…

This article outlines the "over-pruning hypothesis" of autism. The hypothesis originates in a neurocomputational model of the regressive sub-type (Thomas, Knowland & Karmiloff-Smith, 2011a, 2011b). Here we develop a more general version of the over-pruning hypothesis to address heterogeneity in the timing of manifestation of ASD,…

The quality of the home environment, as a predictor, is related to health, education, and emotion outcomes. However, factors influencing the quality of the home environment, as an outcome, have been understudied--particularly how children construct their own environments. Further, most previous research on family processes and outcomes has…

Few studies exist of developmental trajectories in children with intellectual disability, and none for those with subtelomeric deletions. We compared developmental trajectories of children with Wolf-Hirschhorn syndrome to other genetic disorders. We recruited 106 children diagnosed with fragile X, Williams-Beuren syndrome, or Wolf-Hirschhorn…

This study investigated the development of novel metaphor and metonymy comprehension in both typically developing (TD) children and individuals with Williams syndrome (WS). Thirty-one TD children between the ages of 3;09 and 17;01 and thirty-four individuals with WS between the ages of 7;01 and 44 years old were administered a newly developed task…

Background: The capacity to control or regulate one's emotions, cognitions and behavior is central to competent functioning, with limitations in these abilities associated with developmental problems. Parenting appears to influence such self-regulation. Here the differential-susceptibility hypothesis is tested that the more putative "plasticity…

Aberrant attention is a core feature of fragile X syndrome (FXS), however, little is known regarding the developmental trajectory and underlying physiological processes of attention deficits in FXS. Atypical visual attention is an early emerging and robust indicator of autism in idiopathic (non-FXS) autism. Using a biobehavioral approach with gaze…

The present study contrasted physiological arousal in infants and toddlers with fragile X syndrome to typically developing control participants and examined physiological predictors early in development to autism severity later in development in fragile X syndrome. Thirty-one males with fragile X syndrome (ages 8-40 months) and 25 age-matched…

Purpose: To examine the etiology of the relationship between preschool speech and language, and later reading skills. Method: One thousand six hundred seventy-two children from the Twins Early Development Study (B. R. Oliver & R. Plomin, 2007) were given a comprehensive speech and language assessment at 4 1/2 years. Reading was assessed at 7, 9,…

Each year, an increasing number of children are born through surrogacy and thus lack a genetic and/or gestational link with their mother. This study examined the impact of surrogacy on mother-child relationships and children's psychological adjustment. Assessments of maternal positivity, maternal negativity, mother-child interaction, and child…