Tag Archives: IQ

The Bell Curve, 20 years after

Or nearly so. I was planning to publish that blog article for the 31th December 2014. As you can see, I failed in this task, and didn’t finish in the right time. Anyway, I wrote this article, mainly because I … Continue reading

Posted in Behavioral Genetics, Book Review, Psychometrics | Tagged

The study of deaf people since Braden (1994)

Earlier, I have reviewed Braden’s (1994) book, Deafness, Deprivation, and IQ. Considerable amount of studies have been conducted since then. The focus is on the validity of measures of intelligence among the deaf population, such as reliability, predictive validity, measurement … Continue reading

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MH’s book review of Deafness, Deprivation, and IQ (Braden 1994)

Jeffery P. Braden. (1994). Deafness, deprivation, and IQ. Springer. The book is a compilation of studies on deaf people, which concludes that cultural deprivation due to deafness lowers verbal IQ but not nonverbal IQ. Braden sought to prove Arthur Jensen … Continue reading

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Studies of IQ heritability among Chimpanzees

IQ heritability among humans is well-known state of research. Much less has been done on chimpanzees. Hopkins et al. (2014) published a recent study that touches the subject. 99 chimpanzees, aged 9 to 54 (mean = 24.55, SD = 10.67), … Continue reading

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Racial differences in the long-term trend NAEP scores (1975/78-2012)

I analyze the LTT NAEP achievement scores, a public data set available at NCES. In general, minority-majority ethnic groups show a secular decline in d gap, for both math and reading tests, and this occurs at all ages of assessment … Continue reading

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Income mobility according to the Great Gatsby curve : The fantasy of the american dream, statistical artifacts, and the irrelevance of public intervention.

Among the economists, it is commonly held that US people do not experience high income mobility. This is true. But the question of whether US people have lower income or social mobility compared to european countries has no definitive answer. The … Continue reading

Posted in Behavioral Genetics, Economics | Tagged ,

Research on genetic g and differential heritabilities

Multivariate genetic analyses and simple correlational analyses have been conducted to evaluate the extent to which the general factor (g) of intelligence is differentially heritable, compared to, for example, group factors. A positive correlation would be supportive of Jensen’s view, … Continue reading

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Multivariate genetic analysis of cognitive abilities in an adolescent twin sample

The study I want to present here is an important one, although rarely cited in Google Scholar. It shows that the second-order genetic g exists among reaction/inspection time tasks. In reality, some other studies (e.g., Luo et al., 1994; Cardon … Continue reading

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Genotype-Environment Correlation and IQ

Genotype-Environment Correlation and IQ John C. Loehlin and John C. DeFries Received 22 Feb. 1986–Final 22 Jan. 1987 The estimation of various forms of genotype-environment (GE) correlation is considered. Two methods of estimating “passive” GE correlation from adoption studies are … Continue reading

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Structural relationship between g, parental SES, and Achievement : Investigation of the g nexus

The present analysis, using the NLSY97, attempts to model the structural relationship between the latent second-order g factor extracted from the 12 ASVAB subtests, the parental SES latent factor from 3 indicators of parental SES, and the GPA latent factor … Continue reading

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