Table 7.

Estimated heritabilities for SICCT and its components in age-group 1

	${\mathit{\sigma }}_{\mathit{A}}^2$ (SE)	${\mathit{\sigma }}_{\mathit{P}}^2$ (SE)	${\mathit{h}}^2$ (SE)
a 1	0.742 (0.058)	1.156 (0.016)	0.642 (0.043)
b 1	0.817 (0.061)	1.194 (0.017)	0.684 (0.044)
da	0.095 (0.025)	1.964 (0.018)	0.048 (0.013)
db	0.030 (0.016)	2.893 (0.026)	0.010 (0.005)
dc	0.005 (0.013)	2.983 (0.027)	0.002 (0.004)

Analysis of the estimated heritabilities on the first known test within each breakdown for age-group 1