The aim of this study was to assess the effect of family socioeconomic status (SES) and parental education on non-verbal IQ and on the processing of oral and written language, working memory, verbal memory and executive functions in children from different age ranges. A total of 419 Brazilian children aged 6–12 years old, attending public and private schools from Porto Alegre, RS participated i...

BACKGROUND It is not known whether those with co-morbid fragile X syndrome (FXS) and autism represent a distinct subtype of FXS; whether the especially severe cognitive delays seen in studies of young children with co-morbid FXS and autism compared with those with only FXS continue into adolescence and young adulthood; and whether autism in those with FXS is 'true autism', i.e. reflects the sam...

This study considered a relation between rhythm perception skills and individual differences in phonological awareness and grammar abilities, which are two language skills crucial for academic achievement. Twenty-five typically developing 6-year-old children were given standardized assessments of rhythm perception, phonological awareness, morpho-syntactic competence, and non-verbal cognitive ab...

This study tested the hypothesis that children with autism are impaired in using verbal encoding and rehearsal strategies in the service of working memory. Participants were 24 high-ability, school-age children with autism and a comparison group matched on verbal and non-verbal IQ, receptive and expressive vocabulary, and visual memory. Working memory was assessed using verbal and non-verbal va...

Assortative mating, the tendency for mate selection to occur on the basis of similar traits plays an essential role in understanding the genetic variation on academic achievements and intelligence (IQ), it is also an important mechanism explaining spousal concordance. We used a subset of The Collaborative Study on the Genetics of Alcoholism sample to study the mating patterns in 84 pairs of spo...

Background: Congenital hypothyroidism (CH) is one of the preventable causes of intellectual disability. The aim of this study was to compare intelligence quotient (IQ) in early treated children with CH and healthy children. Materials and Methods: This cohort study was conducted on 78 early tre...

BACKGROUND Autism spectrum disorder (ASD) was once considered to be highly associated with intellectual disability and to show a characteristic IQ profile, with strengths in performance over verbal abilities and a distinctive pattern of 'peaks' and 'troughs' at the subtest level. However, there are few data from epidemiological studies. METHOD Comprehensive clinical assessments were conducted...

Intelligence levels and intelligence profiles were investigated in 52 members of a large family with the fragile X syndrome. The mental abilities were evaluated by the three Wechsler intelligence tests (WAIS, WISC-R, and WPPSI). Chromosomal and psychological data were then compared. In 22 non-retarded fra(X) negative family members, a mean IQ of 102 was found (males 97, females 106). Eleven non...

Sir, Anderson et al. (2009) refuted the Kennard Principle, which states that the immature brain is more plastic and less vulnerable to insult than a mature brain (Montour-Proulx et al., 2004); however, there are important errors in Table 5 of their paper. The IQ data for their six age subgroups do not tally with the total group figures in the last column of Table 5. In each of these six subgrou...

OBJECTIVE This study evaluated the relationship between prenatal exposure to airborne polycyclic aromatic hydrocarbons (PAHs) and child intelligence. METHODS Children of nonsmoking black or Dominican-American women residing in New York City were monitored from in utero to 5 years of age, with determination of prenatal PAH exposure through personal air monitoring for the mothers during pregnan...