Twin Differentiation of Cognitive Ability Through Phenotype to Environment Transmission: The Louisville Twin Study.
The Louisville Twin Study is one of the most intensive twin studies of cognitive ability. The repeated measurements of the twins are ideal for testing developmental twin models that allow for the accumulation of gene-environment correlation via a (P⇒E) transmission process to explain twins' divergence in mean ability level over time. Using full-scale IQ scores from 566 pairs of twins (MZ = 278; DZ = 288), we tested whether a P⇒E transmission model provided better representation of actual developmental processes than a genetic simplex model. We also addressed whether the induced gene-environment correlation alters the meaning of the latent nonshared environmental factors with a simple numerical method for interpreting nonshared environmental factors in the context of P⇒E transmission. The results suggest that a P⇒E model provided better fit to twins' FSIQ data than a genetic simplex model and the meaning of the nonshared environment was preserved in the context of P⇒E.
['Beam|Christopher R|CR|http://orcid.org/0000-0001-6827-409X', 'Turkheimer|Eric|E|', 'Dickens|William T|WT|', 'Davis|Deborah Winders|DW|']
D000293:Adolescent D002648:Child D002657:Child Development D002675:Child, Preschool D005260:Female D059647:Gene-Environment Interaction D006801:Humans D007223:Infant D007360:Intelligence D008297:Male D008957:Models, Genetic D010641:Phenotype D014429:Twins, Dizygotic D014430:Twins, Monozygotic
Louisville Twin Study Genetic simplex Nonshared environment Cognitive development Intelligence