Table 3.

Heritability, shared, nonshared, and identified environmental influence (along the diagonals) in Boston Naming Test years 1, 2 and 3 estimated from longitudinal expanded model. The off-diagonals represent parameter estimates of the genetic and environmental contributions to the correlation between longitudinal assessments of the Boston Naming Test [95% confidence intervals]

		Year 1	Year 2	Year 3
Boston Naming Test
A	Year 1	.32 [.16–.53]
	Year 2	.35 [.20–.51]	.37 [.22–.56]
	Year 3	.40 [.24–.60]	.44 [.28–.63]	.54 [.31–.80]
C	Year 1	.37 [.18–.57]
	Year 2	.39 [.21–.57]	.42 [.23–.61]
	Year 3	.27 [.08–.46]	.28 [.09–.47]	.26 [.03–.50]
E	Year 1	.24 [.19–.30]
	Year 2	.06 [.03–.11]	.17 [.13–.22]
	Year 3	.07 [.03–.12]	.06 [.02–.10]	.15 [.10–.21]
Home Literacy
Environment Year 1		.08 [.03–.15]
	Year 2	.05 [.01–.12]	.04 [.01–.10]
	Year 3	.07 [.02–.13]	.06 [.02–.12]	.07 [.02–.15]