. Author manuscript; available in PMC: 2007 Jun 4.

Published in final edited form as: Am J Speech Lang Pathol. 2007 May;16(2):169–178. doi: 10.1044/1058-0360(2007/021)

Table 7.

Standardised parameter estimates for best fitting models with 95% confidence intervals (CIs) in different age groups (unaffected /affected) for the best-fitting models (as indicated in Table 5).

	A	C	E	Threshold
AGE 3

Boys				1.78 (1.72 - 1.85)
	.58 (.44 - .71)	n/a	.42 (.29- .56)
Girls				2.00 (1.92 - 2.07)
AGE 4

Boys				1.68 (1.63 - 1.73)
	.65 (.54 - .74)	n/a	.35 (.26 - .46)
Girls				1.97 (1.91 - 2.04)
AGE 7

Boys				2.00 (1.93 - 2.07)
	.66 (.51 - .78)	n/a	.34 (.22 - .49)
Girls				2.38 (2.29 - 2.47)

Abbreviations: A = additive genetic influences, C = common (shared environmental influences), E = unique environmental influences

Note: Threshold values refer to equivalent cutoff values in normal distributions (i.e. a threshold value of 1.78 refers to the top 3.7% of the distribution). The non-overlapping threshold values for boys and girls indicate the fact that affected girls are at the higher end of the distribution compared to boys.