Heritability

The proportion of the variation in pheno-type that can be explained by genetic variation among indi viduals. In other words, heritability is the extent to which genetic differences contribute to individual differences in observed behaviors or traits. The error in heritability esti mates is generally high unless the sample size is very large. For human behavior, almost all estimates of heritability are in the moderate range of .30 to .60. It is important to note that heritability is a population concept. A heritability of .30 for a particular trait means that, on average, about 30% of the individual differences observed on that trait in the population may be attributable to genetic variation. It does not mean that for a given individual 30% of the observed trait is due to his or her genes. For more information, see the Stanford Encyclopedia of Philosophy entry “Heredity and Heritability” (http://plato.stanford.edu/entries/heredity/).