Keywords: Layzer.png graph made by me to illustrate heritability and environmental effects on a trait Based on a graph in Layzer David 1974 Heritability analyses of IQ scores Science or numerology Science 183 1259-66 Own 2008-04-11 Wobble PD Layzer David 1974 Heritability analyses of IQ scores Science or numerology Science 183 1259-66 Psychology Population genetics |