Category Archives: Psychometrics

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

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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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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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Transracially adopted intermediate IQ : Hereditarian nonsense

A bad, invalid argument commonly used by hereditarians is the research concerning transracial adoption. The claim usually made is that black, black-white mixed-race, white, asian-white mixed-race adoptees had IQs following the well-established genetic hierarchy seemingly B < BW < W < … Continue reading

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Flynn contra Rushton on principal component analysis : A failed replication

While Rushton (1999) demonstrates, using PCA, that g and black-white differences were related, with Flynn Effect (FE) gains over time showing no relationship with the aforementioned variables, Flynn (2000) has challenged Rushton in arguing that Wechsler’s subtest loadings on the … Continue reading

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IQ Testing : From Correlation to Causation

It is well known and acknowledged that IQ correlates with social outcomes (Herrnstein & Murray, 1994; Jensen, 1980, 1998; Gottfredson, 1997), measures of health (Gottfredson, 2004, & Deary, 2004; Reeve & Basalik, 2010), wages (Jones & Schneider, 2008), savings (Jones, 2012), job performance (Ree & Earles, 1994; Schmidt … Continue reading

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Jensen effect on racial IQ differences and GPA controlling for SES in the NLSY79 and NLSY97

In The g Factor, Jensen (1998, pp. 384-385) states that because races differ in SES levels, the Spearman-Jensen effect (i.e., g-loading correlates) found in racial IQ differences (hispanics, denoted H; blacks, denoted B; whites, denoted W) could simply reflect this … Continue reading

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A Further Comment on the Meta-Analytic Jensen Effect on Heritability and Environmentality of Cognitive Tests

I discussed at length the results at Human Varieties. I will simply add some more important comments here. A lot of problems must be highlighted. Although large positive g*h2 and modest negative g*c2 correlations were found, heterogeneity of effect sizes … Continue reading

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Investigation of the relationship between mental retardation with heritability and environmentality of the Wechsler subtests

The present analysis is an extension of Spitz’s earlier (1988) study on the relationship between mental retardation (MR) lower score and subtest heritability (h2) and g-loadings. These relationships were found to be positive. But Spitz himself haven’t tested the possibility … Continue reading

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