The second step also provides us with the fraction of phenotypic variance explained by the empirically estimated relatedness matrix. We call this fraction pseudoheritability because it resembles the heritability estimated from a pedigree26, although this is not directly interchangeable with heritability of the trait because the estimated pairwise relatedness does not correspond exactly to the kinship coefficients. Nonetheless, the pseudoheritability estimates are concordant with the previous heritability estimates from a large family based study of Kosrae and Sardinian populations27,28. Different methods for estimating the pairwise relatedness provide slightly different but highly correlated estimates of pseudoherit-ability across the ten traits. (Supplementary Table 1).
