Brain development parameters and intelligence in Chilean high school graduates

Twelve-year follow-up study of the impact of nutritional status at the onset of elementary school on later educational situation of Chilean school-age children

“…From the results presented here, we may hypothesize that children with suboptimal HC may have alterations of brain development which become associated with the lowered SES, SA and IA, variables that in the current study contributed to determine the educational results; independent of SES and sex, differences in human brain size are relevant to explain differences in intelligence test performance (Ivanovic et al, 1996(Ivanovic et al, , 2000a(Ivanovic et al, , b, c, 2001(Ivanovic et al, , 2002(Ivanovic et al, , 2004aReiss et al, 1996;Botting et al, 1998;Strauss and Dietz, 1998;Toro et al, 1998;Pennington et al, 2000). These studies found positive and significant correlations between HC, SA, IA, brain and parental HC; however, an absence of correlations between brain size, HC and intelligence has been reported in studies of monozygotic twins or in sisters (Tramo et al, 1998;Schoenemann et al, 2000).…”

“…Similar results were observed when quantitating the impact of the nutritional status upon SA and IA assessed through the Raven Progressive Matrices Test, HC being the most important anthropometric parameter (Ivanovic et al, 1996(Ivanovic et al, , 2000bToro et al, 1998). It has been defined as the most sensitive anthropometric marker of prolonged undernutrition during infancy, associated with decreased SA and IA (Stoch et al, 1982;Ivanovic et al, 2000bIvanovic et al, , 2004a.…”

“…School-age children from the low SES achieve significantly lower in SA and intelligence tests and tend to have a negative nutritional background manifested mainly through a smaller HC compared to their peers from the higher socio-economic strata (Singh and Arvind, 1986;Ivanovic 1988;Ivanovic and Ivanovic, 1990;Ivanovic et al, 1995aIvanovic et al, , 1996Ivanovic et al, , 2000aIvanovic et al, , b, c, 2001Ivanovic et al, , 2002Ivanovic et al, , 2004aKramer et al, 1995;Brown and Pollitt, 1996;Toro et al, 1998).…”

Big-brained people are smarter: A meta-analysis of the relationship between in vivo brain volume and intelligence

“…Some of the 23 sample difference is due to differing decision rules. For this paper, correlations are reported separately by sex for six studies (Andreasen et al, 1993;Gur et al, 1999;Ivanovic et al, 2004;Reiss, Abrams, Singer, Ross, and Denckla, 1996;Tan et al, 1999;Willerman, 1991) while Gignac et al reported a single correlation for males and females combined for five of the studies and did not include data from Ivanovic et al (2004). This reduced the number of different samples to 18.…”

Males have greater g: Sex differences in general mental ability from 100,000 17- to 18-year-olds on the Scholastic Assessment Test

“…Additional data on sex differences in brain size were reviewed by Rushton and Ankney (1996) who confirmed the male advantage; they also reviewed the relation between brain size and cognitive ability, which they found to be 0.20 using external head size measures and 0.40 using magnetic resonance imaging, or MRI. Subsequently, Pakkenberg and Gundersen (1997) documented that men have 15% more neurons than women (22.8 versus 19.3 billion), and over two-dozen MRI studies have confirmed the brainsize/IQ correlation of about 0.40 (e.g., Ivanovic et al, 2004;McDaniel, 2005). Lynn (1999, p. 1) dubbed the findings on sex differences in brain size "the Ankney-Rushton anomaly."…”