Table 3.

Summary of genetic and common environmental contribution estimates at single data points for each tract.

	No. of data points	FA			AD			RD
		a2, mean [range]	% of significant points of a2	c2, mean [range]	a2, mean [range]	% of significant points of a2	c2, mean [range]	a2, mean [range]	% of significant points of a2	c2, mean [range]
Corpus callosum
rostrum, orbitofrontal	95	0.24 [0–0.46]	45.3	0.03 [0–0.19]	0.07 [0–0.59]	16.8	0.21 [0–0.39]	0.32 [0–0.52]	74.7	0.05 [0–0.27]
genu, prefrontal	94	0.25 [0–0.58]	66.0	0.07 [0–0.33]	0.14 [0–0.50]	38.3	0.22 [0–0.41]	0.31 [0–0.54]	79.8	0.09 [0–0.34]
body, premotor	92	0.33 [0–0.71]	73.9	0.02 [0–0.14]	0.19 [0–0.57]	39.1	0.21 [0–0.39]	0.37 [0–0.69]	81.5	0.08 [0–0.40]
body, motor	87	0.35 [0–0.58]	67.8	0.03 [0–0.21]	0.14 [0–0.62]	31.0	0.18 [0–0.36]	0.33 [0–0.64]	70.1	0.06 [0–0.28]
body, parietal	128	0.28 [0–0.63]	64.8	0.06 [0–0.24]	0.10 [0–0.54]	17.2	0.20 [0–0.37]	0.30 [0–0.54]	73.4	0.06 [0–0.33]
splenium, occipital	152	0.39 [0–0.70]	71.7	0.05 [0–0.24]	0.10 [0–0.50]	16.4	0.16 [0–0.31]	0.31 [0–0.55]	67.1	0.09 [0–0.36]
tapetum, temporal	181	0.31 [0–0.54]	66.3	0.05 [0–0.33]	0.19 [0–0.64]	29.8	0.18 [0–0.45]	0.26 [0–0.64]	50.8	0.10 [0–0.33]
Corticothalamic tract
prefrontal, left	81	0.29 [0–0.52]	63.0	0.02 [0. –0.26]	0.13 [0–0.47]	46.9	0.20 [0–0.27]	0.18 [0–0.52]	48.1	0.10 [0–0.28]
prefrontal, right	79	0.23 [0–0.40]	55.7	0.04 [0–0.31]	0.14 [0–0.50]	50.6	0.21 [0–0.45]	0.15 [0–0.50]	43.0	0.16 [0–0.31]
premotor, left	79	0.25 [0–0.53]	50.6	0.03 [0–0.26]	0.10 [0–0.58]	26.6	0.20 [0–0.41]	0.23 [0–0.50]	62.0	0.08 [0–0.22]
premotor, right	80	0.23 [0–0.46]	40.0	0.09 [0–0.33]	0.13 [0–0.53]	50.0	0.23 [0–0.43]	0.22 [0–0.48]	61.3	0.13 [0–0.29]
motor, left	80	0.16 [0–0.44]	28.8	0.11 [0–0.32]	0.15 [0–0.59]	53.8	0.17 [0–0.37]	0.22 [0–0.52]	57.5	0.09 [0–0.26]
motor, right	82	0.23 [0–0.55]	50.0	0.08 [0–0.29]	0.14 [0–0.64]	51.2	0.21 [0–0.46]	0.24 [0–0.52]	59.8	0.11 [0–0.27]
parietal, left	68	0.23 [0–0.43]	45.6	0.07 [0–0.26]	0.07 [0–0.55]	35.3	0.23 [0–0.41]	0.18 [0–0.49]	50.0	0.13 [0–0.28]
parietal, right	64	0.31 [0–0.58]	62.5	0.04 [0–0.23]	0.13 [0–0.67]	48.4	0.23 [0–0.46]	0.24 [0–0.49]	65.6	0.10 [0–0.25]
Corticofugal tract
prefrontal, left	109	0.24 [0–0.41]	54.1	0.04 [0–0.26]	0.06 [0–0.40]	27.5	0.25 [0–0.45]	0.12 [0–0.42]	36.7	0.15 [0–0.33]
prefrontal, right	110	0.18 [0–0.36]	32.7	0.07 [0–0.26]	0.09 [0–0.48]	35.5	0.22 [0–0.59]	0.11 [0–0.44]	35.5	0.17 [0–0.32]
premotor, left	112	0.20 [0–0.52]	40.2	0.07 [0–0.30]	0.09 [0–0.58]	28.6	0.24 [0–0.43]	0.16 [0–0.50]	49.1	0.13 [0–0.30]
premotor, right	117	0.23 [0–0.46]	39.3	0.06 [0–0.29]	0.33 [0–0.61]	53.0	0.08 [0–0.33]	0.22 [0–0.48]	59.0	0.09 [0–0.24]
motor, left	121	0.21 [0–0.53]	46.3	0.09 [0–0.34]	0.12 [0–0.62]	48.8	0.20 [0–0.42]	0.18 [0–0.55]	45.5	0.12 [0–0.27]
motor, right	122	0.23 [0–0.61]	45.9	0.08 [0–0.36]	0.09 [0–0.56]	31.1	0.23 [0–0.47]	0.18 [0–0.54]	41.0	0.11 [0–0.33]
parietal, left	120	0.22 [0–0.54]	48.3	0.07 [0–0.31]	0.06 [0–0.34]	27.5	0.21 [0–0.40]	0.15 [0–0.44]	41.7	0.10 [0–0.26]
parietal, right	119	0.24 [0–0.72]	40.3	0.07 [0–0.29]	0.11 [0–0.58]	39.5	0.19 [0–0.50]	0.14 [0–0.53]	29.4	0.11 [0–0.33]
Medial lemniscal pathway
Left	42	0.14 [0–0.45]	16.7	0.08 [0–0.27]	0.12 [0–0.37]	16.7	0.13 [0–0.33]	0.14 [0–0.30]	14.3	0.10 [0–0.28]
Right	42	0.10 [0–0.36]	9.5	0.08 [0–0.30]	0.12 [0–0.43]	0.0	0.14 [0–0.28]	0.09 [0–0.43]	0.0	0.18 [0–0.33]
Cingulum
cingulate gyrus, left	86	0.20 [0–0.39]	16.3	0.06 [0–0.25]	0.12 [0–0.46]	14.0	0.10 [0–0.40]	0.15 [0–0.36]	31.4	0.08 [0–0.26]
cingulate gyrus, right	79	0.10 [0–0.32]	0.0	0.09 [0–0.26]	0.12 [0–0.41]	19.0	0.13 [0–0.35]	0.18 [0–0.42]	35.4	0.08 [0–0.25]
hippocampal, left	104	0.32 [0–0.60]	42.3	0.06 [0–0.35]	0.02 [0–0.32]	2.9	0.21 [0–0.32]	0.13 [0–0.53]	31.7	0.16 [0–0.36]
hippocampal, right	102	0.37 [0–0.59]	61.8	0.05 [0–0.30]	0.03 [0–0.31]	2.9	0.17 [0–0.41]	0.13 [0–0.49]	25.5	0.14 [0–0.30]
Fornix
Left	142	0.30 [0–0.52]	62.0	0.08 [0–0.50]	0.20 [0–0.61]	37.3	0.18 [0–0.42]	0.24 [0–0.62]	47.9	0.14 [0–0.36]
Right	146	0.37 [0–0.66]	64.4	0.05 [0–0.37]	0.42 [0–0.81]	62.3	0.08 [0–0.38]	0.46 [0–0.85]	67.1	0.05 [0–0.34]
Arcuate fasciculus
fronto-parietal, left	70	0.28 [0–0.51]	51.4	0.03 [0–0.32]	0.05 [0–0.43]	7.1	0.21 [0–0.37]	0.27 [0–0.44]	74.3	0.11 [0–0.30]
fronto-parietal, right	61	0.31 [0–0.48]	59.0	0.03 [0–0.28]	0.17 [0–0.54]	36.1	0.17 [0–0.39]	0.38 [0–0.53]	91.8	0.06 [0–0.21]
fronto-temporal, left	117	0.15 [0–0.46]	23.9	0.14 [0–0.30]	0.07 [0–0.32]	4.3	0.17 [0–0.40]	0.24 [0–0.47]	59.8	0.08 [0–0.21]
fronto-temporal, right	106	0.25 [0–0.54]	39.6	0.05 [0–0.24]	0.05 [0–0.48]	11.3	0.24 [0–0.40]	0.25 [0–0.50]	70.8	0.13 [0–0.28]
temporo-parietal, left	79	0.10 [0–0.38]	8.9	0.10 [0–0.32]	0.10 [0–0.48]	12.7	0.13 [0–0.36]	0.17 [0–0.49]	45.6	0.10 [0–0.28]
temporo-parietal, right	76	0.19 [0–0.40]	36.8	0.06 [0–0.23]	0.01 [0–0.41]	2.6	0.25 [0–0.36]	0.20 [0–0.37]	2.6	0.12 [0–0.29]
Uncinate fasciculus
Left	90	0.23 [0–0.46]	55.6	0.05 [0–0.25]	0.07 [0–0.43]	20.0	0.24 [0–0.38]	0.17 [0–0.45]	51.1	0.11 [0–0.26]
Right	87	0.20 [0–0.49]	41.4	0.06 [0–0.25]	0.07 [0–0.45]	41.4	0.18 [0–0.32]	0.13 [0–0.43]	41.4	0.12 [0–0.28]
Sup. longitudinal fasciculus
Left	75	0.21 [0–0.44]	36.0	0.03 [0–0.26]	0.02 [0–0.25]	0.0	0.25 [0–0.43]	0.23 [0–0.44]	58.7	0.12 [0–0.31]
Right	70	0.24 [0–0.46]	38.6	0.02 [0–0.24]	0.13 [0–0.52]	25.7	0.15 [0–0.41]	0.26 [0–0.51]	62.9	0.11 [0–0.26]
Inf. longitudinal fasciculus
Left	100	0.29 [0–0.50]	57.0	0.05 [0–0.26]	0.02 [0–0.31]	0.0	0.24 [0–0.34]	0.24 [0–0.48]	62.0	0.09 [0–0.31]
Right	100	0.23 [0–0.56]	36.0	0.05 [0–0.22]	0.05 [0–0.48]	5.0	0.23 [0–0.41]	0.22 [0–0.54]	42.0	0.11 [0–0.28]
Inf. fronto-occipital fasciculus
Left	158	0.27 [0–0.55]	58.9	0.08 [0–0.34]	0.11 [0–0.49]	20.9	0.21 [0–0.41]	0.25 [0–0.46]	61.4	0.08 [0–0.29]
Right	152	0.26 [0–0.49]	54.6	0.07 [0–0.28]	0.11 [0–0.64]	22.4	0.23 [0–0.40]	0.26 [0–0.50]	69.1	0.10 [0–0.35]
Optic tract
Left	70	0.20 [0–0.45]	38.6	0.05 [0–0.38]	0.13 [0–0.61]	25.7	0.12 [0–0.40]	0.13 [0–0.61]	28.6	0.11 [0–0.40]
Right	66	0.19 [0–0.44]	10.6	0.09 [0–0.32]	0.12 [0–0.65]	19.7	0.14 [0–0.45]	0.17 [0–0.70]	25.8	0.10 [0–0.29]