Gene-environment (GxE) Interaction Twin Studies of SES and Cognitive Measures.

<$>\vskip -3\scale 65%\raster="rg1"<$>indicates studies considered to have unreliable estimates based on small samples and/or non-standard zygosity assignment. a15% cut-offs for low and high SES (non-significant estimates for 25%, 33% and 50% cut-offs also reported in original paper). bNot reported. cGxE significant for change in mental ability from 1 to 2 years. dNo zygosity information; MZ and DZ twin correlations estimated from data from same-sex and opposite-sex twins. eResults averaged over 5 tests and 2 ethnic groups.