Results from a genome-wide association study (GWAS) can be used to generate a polygenic score (PGS), an individual-level measure summarizing identified genetic influence on a trait dispersed across the genome. For complex, behavioral traits, the association between an individual's PGS and their phenotype may contain bias (from geographic,…

Observed genetic associations with educational attainment may be due to direct or indirect genetic influences. Recent work highlights "genetic nurture," the potential effect of parents' genetics on their child's educational outcomes via rearing environments. To date, few mediating childhood environments have been tested. We used a large…

While there is a strong sex bias in the presentation of autism, it is unknown whether this bias is also present in subclinical manifestations of autism among relatives, or the broad autism phenotype. This study examined this question and investigated patterns of co-occurrence of broad autism phenotype traits within families of individuals with…

The broad autism phenotype (BAP) refers to the phenotypic expression of an underlying genetic liability to autism, manifest in non-autistic relatives. This study examined the relationship among the "Broad Autism Phenotype Questionnaire" (BAPQ), "Social Responsiveness Scale: Adult Research Version" (SRS:ARV), and "Family…

Purpose: Researchers have previously shown that individual differences in measures of receptive language ability at age 12 are highly heritable. In the current study, the authors attempted to identify some of the genes responsible for the heritability of receptive language ability using a "genome-wide association" approach. Method: The…

The link between parental autistic tendency and anxiety symptoms was studied in 491 Taiwanese couples raising biological children with autism spectrum disorders (ASDs). Parental autistic tendency as measured by Autism Spectrum Quotient (AQ) was associated with anxiety symptoms across all domains. Large effect sizes were found in social phobia and…

Purpose: To evaluate phenotypic expressions of speech sound disorder (SSD) in multigenerational families with evidence of familial forms of SSD. Method: Members of five multigenerational families (N = 36) produced rapid sequences of monosyllables and disyllables and tapped computer keys with repetitive and alternating movements. Results: Measures…

It is well established that speech, language and phonological skills are closely associated with literacy, and that children with a family risk of dyslexia (FRD) tend to show deficits in each of these areas in the preschool years. This paper examines what the relationships are between FRD and these skills, and whether deficits in speech, language…

Background: Twin studies in children reveal that familial aggregation of anxiety disorders is due to both genetic and environmental factors. Cognitive biases for threat information are considered a robust characteristic of childhood anxiety. However, little is known regarding the underlying aetiology of such biases and their role in anxiety…

This study investigated the mean-level and individual-level trends as well as the genetic and environmental sources of rank-order continuity and change in temperament traits ("Briskness, Perseveration, Sensory Sensitivity, Emotional Reactivity, Endurance, and Activity"). We analyzed self-reports and peer ratings from 2 adult age groups…

This study examined the validity of the Klonoff and Landrine Illness-Belief Scale when applied to Latino college students (n = 156; 34% male, 66% female) at high risk for future diabetes onset. Principal factor analysis yielded four significant factors--emotional, folk beliefs, punitive, gene/hereditary--which accounted for 64.5% of variance and…

One interpretation of the Pearson product-moment correlation ("r"), correlation as the probability of originating from common descent, important to the genetic measurement of inbreeding, is examined. The conditions under which "r" can be interpreted as the probability of "identity by descent" are specified, and the…

The relation between intelligence and birth order was shown in a recent publication [Bjerkedal, T., Kristensen, P., Skjeret, G. A. & Brevik, J. I. (2007). Intelligence test scores and birth order among young Norwegian men (conscripts) analyzed within and between families. "Intelligence," 35, 503-514] to be negative. Subjects in this…

A literature review of autism and tuberous sclerosis complex (TSC) substantiates a significant association between the two. Studies of 14 autistic probands and 13 TSC probands identified 7 TSC subjects with autism, who had more seizures and mental retardation than those without autism. More male TSC probands with autism than female were…

A geneticist discusses the heritability of intelligence and points out the pitcalls that lie in the path of those who try to estimate the heritability of IQ differences. (Editor)