TABLE 12.

MZ AND DZ PROBANDWISE CONCORDANCES AND RESULTS OF DF EXTREMES ANALYSIS USING 15% CUTOFFS

	Probandwise concordance		Twin group correlation		DF estimates
	MZ	DZ	MZ	DZ	h2g (SE)	c2g (SE)
7-year NC English	.76	.44	.85	.47	.75 (.07)	.10 (.05)
7-year NC Math	.73	.46	.81	.46	.69 (.08)	.11 (.06)
9-year NC English	.71	.38	.82	.40	.83 (.09)	.00 (.07)
9-year NC Math	.68	.36	.75	.31	.89 (.10)	.00 (.07)
9-year NC Science	.77	.44	.79	.42	.75 (.10)	.04 (.07)
10-year NC English	.71	.37	.82	.40	.84 (.09)	.00 (.07)
10-year NC Math	.70	.40	.79	.42	.75 (.10)	.04 (.07)
10-year NC Science	.68	.46	.76	.46	.58 (.11)	.17 (.08)
7-year TOWRE	.71	.47	.88	.55	.65 (.06)	.23 (.05)
10-year PIAT	.48	.36	.63	.42	.43 (.11)	.20 (.08)
10-year Web Math	.46	.36	.64	.40	.47 (.10)	.16 (.07)
7-year g	.52	.38	.68	.47	.42 (.07)	.26 (.05)
9-year g	.60	.44	.73	.55	.37 (.08)	.37 (.06)
10-year g	.57	.36	.72	.46	.52 (.09)	.20 (.07)

Note.—7-year NC English: 1,170 families (1,632 probands) 392 MZ pairs, 778 DZ pairs.

7-year NC Math: 1,174 families (1,634 probands) 386 MZ pairs, 788 DZ pairs.

9-year NC English: 566 families (756 probands) 183 MZ pairs, 383 DZ pairs.

9-year NC Math: 554 families (732 probands) 198 MZ pairs, 356 DZ pairs.

9-year NC Science: 531 families (739 probands) 172 MZ pairs, 359 DZ pairs.

10-year NC English: 580 families (775 probands) 197 MZ pairs, 383 DZ pairs.

10-year NC Math: 571 families (769 probands) 193 MZ pairs, 378 DZ pairs.

10-year NC Science: 560 families (772 probands) 207 MZ pairs, 353 DZ pairs.

7-year TOWRE: 1,063 families (1,476 probands) 369 MZ pairs, 694 DZ pairs.

10-year PIAT: 470 families (589 probands) 176 MZ pairs, 294 DZ pairs.

10-year Web Math: 615 families (768 probands) 221 MZ pairs, 394 DZ pairs.

7-year g: 1,142 families (1,461 probands) 429 MZ pairs, 713 DZ pairs.

9-year g: 674 families (901 probands) 247 MZ pairs, 427 DZ pairs.

10-year g: 580 families (745 probands) 214 MZ pairs, 366 DZ pairs.

MZ, monozygotic; DZ, dizygotic; h²g, group heritability; c²g, group shared environment.