Table 1.

Distributions of Reading Measures in All Members of the 79 Families, in the All-Ages Sib-Pair Sample, and in the Sample of Sib Pairs <18 Years of Age^[Note]

Trait	N	Mean	SD	Minimum	Maximum	Skewness	Kurtosis
Phonological awareness:a
All family members	509	17.05	5.67	1	28.44b	−.79	−.07
All-ages sib pairs	202	17.02	5.56	2.65	28.44b	−.48	−.58
Sib pairs <18 years of age	163	16.96	5.75	2.65	28.44b	−.41	−.69
Phonological coding:c
All members	610	98.03	17.28	12	149	−.03	1.01
All-ages sib pairs	223	89.69	15.11	46	149	.53	1.14
Sib pairs <18 years of age	180	88.52	14.65	46	129	.33	.63
Spelling:c
All members	599	90.85	16.33	47	124	−.20	−.90
All-ages sib pairs	215	81.36	14.14	47	115	.51	−.29
Sib pairs <18 years of age	172	80.51	13.86	47	115	.66	−.02
RAN speed:a
All members	599	3.08	.62	1.09	5.00	.16	−.13
All-ages sib pairs	218	2.96	.56	1.45	4.64	.23	.04
Sib pairs <18 years of age	176	2.99	.56	1.59	4.64	.33	.12

Note.—A minority of subjects did not complete all psychometric tests, leading to different sample sizes between traits. For all traits, lower scores indicate greater deficit.

^aData are raw scores for adult subjects and age-adjusted scores for subjects <18 years of age.

^bAge adjustment in subjects <18 years of age occasionally resulted in scores that surpassed the number of test trials of 23.

^c Data are standard scores, according to test norms (normal population mean = 100, SD = 15).