Children With Superior Intelligence at 7 Years of Age

Abstract

Perinatal and medical information, growth, and the social background of 258 children who, in a prospective study, had superior intelligence at 7 years of age were reviewed. The subjects were divided into three categories on the basis of the results of psychological evaluation at age 7. Comparisons were made between those with superior (intelligence quotient greater than or equal to 120), average (IQ between 80 and 119), and low intelligence (IQ less than or equal to 79). A favorable parental social and educational background was the best correlate of superior intelligence in the children. Larger head size from 1 year of age was an early finding associated with superior intelligence. Greater height and weight, from 4 years of age were later findings. Correlations between psychological performance at ages 4 and 7 years were statistically significant. Perinatal factors and medical complications did not affect the intellectual status of children with superior intelligence.

The Influence of Head Growth in Fetal Life, Infancy, and Childhood on Intelligence at the Ages of 4 and 8 Years

“…[1][2][3][4] Similar associations have been found in adults. 5,6 Maximal brain volume is usually achieved between the ages of 5 and 10 years, 7 but rates of brain growth are highest in the last part of gestation and the first 1 year of life.…”

“…Our findings, derived by distinguishing the effects of brain growth during different periods of development, suggest that these associations between head circumference and intelligence in later childhood owe more to the influence of brain growth during infancy than they do to growth after infancy; the findings fit with observations in a cohort of 2023 children that those with IQ scores in the superior range (scores of Ն120) at the age of 7 years had larger head circumferences at 1 year of age than did children whose IQ scores were average (scores of 80 -119). 2 In a recent study, higher IQ scores at the age of 9 years were associated with increased head growth both in the first 9 months of life and between 9 months and 9 years of age, regardless of head size at the start of these periods, but detailed information on growth after 9 months of age was not available. 1 Results from some small studies of very low birth weight infants have indicated that the critical period for catch-up brain growth, in terms of later intelligence, may be confined to the first 1 year of life.…”

Common variants at 12q15 and 12q24 are associated with infant head circumference

“…Normal variation in head circumference seems to be associated with cognitive and behavioral development 8-10 . Larger head circumference in infancy is associated with higher IQ scores in childhood 10-12 . The underlying mechanisms however, are poorly understood.…”

Body Size and Intelligence in 6-year-olds: Are Offspring of Teenage Mothers at Risk?

“…Other research has reported that lower IQ is correlated with smaller head circumference [30-32]. In order to examine this relation, we entered head circumference into our final regression models with the composite score and the area scores as our outcome variables (Table 4).…”

“…The larger the brain, the higher the test scores [32, 42-44]. Two additional studies have shown that the brain volume achieved by age 1 predicts intelligence in later childhood [31, 45]. Shaw et al [38] demonstrated that the thickness of the cerebral cortex is correlated with intelligence.…”