In genetics, Heritability's the proportion of phenotypic variation in a population that's attributable to genetic variation among individuals. Variation among individuals may be due to genetic and/or environmental factors. Heritability analyses estimate the relative contributions of differences in genetic and non-genetic factors to the total phenotypic variance in a population. Definition Consider a statistical model for describing some particular phenotype: » Phenotype (P) = Genotype (G) + Envi… (More on Heritability)