Table 3.

Genomic-Relatedness-Matrix Restricted Maximum Likelihood Estimation (GREML)-based Estimates of the Heritability of Years of Schooling, by Sample

Framingham Heart Study (N = 932)
V(G): Variance in genotype	3.81 (1.68)
V(e): Residual error	3.28 (1.64)
V(P): Variance in phenotype	7.09 (0.33)
V(G)/V(P)	0.54 (0.23)
logL	−1, 377.16
logL0	−1, 382.52
Likelihood Ratio Test	10.73
p-value (df = 1)	0.001
Health and Retirement Study (N = 6,186))
V(G): Variance in genotype	1.20 (0.59)
V(e): Residual error	4.90 (0.49)
V(P): Variance in phenotype	6.10 (0.16)
V(G)/V(P)	0.20 (0.09)
logL	−7, 700.68
logL0	−7, 703.49
Likelihood Ratio Test	5.62
p-value (df =1)	0.009

Note: Standard errors in parentheses.