Monthly Archives: April 2014

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

Posted in Behavioral Genetics | Tagged

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

Posted in Behavioral Genetics, Stats | Tagged

Against bad use of correlations

Orlich & Gifford (2006) published an analysis that shows high correlation between parental income and SAT scores. All those correlations are close to 100%, in fact, around 0.97 or 0.98. This is more than twice the usual effect size we … Continue reading

Posted in Stats