. Author manuscript; available in PMC: 2014 Jun 20.

Published in final edited form as: Child Dev. 2014 Jan 6;85(3):1190–1205. doi: 10.1111/cdev.12207

Table 1. Sample Ns and Phenotypic Correlations (95% Confidence Intervals in Parentheses).

		Twin analyses
	GCTA (n)	MZ	DZ	n pairs	Phenotypic r
TOWRE₇–TOWRE₁₂	2,942	535	748	1,283	0.69 (0.66-0.61)
TOWRE₇–ART₁₂	2,931	575	834	1,409	0.46 (0.43-0.49)
TOWRE₁₂–ART₁₂	2,598	422	644	1,066	0.43 (0.39-0.47)

Note. Subscript indicates age (7 or 12 years) at which measure was administered. Phenotypic r estimates based on GCTA sample. GCTA = genome-wide complex trait analysis; MZ = monozygotic twins; DZ = dizygotic twins; TOWRE = Test of Word Reading Efficiency; ART = Author Recognition Test.