Table 2.

Psychological variables of the study participants in the cross-sectional analyses (127 boys and 135 girls, upper lines) and their change in the longitudinal analyses (106 boys and 102 girls, lower lines when there are two lines)

Measure	Boys	Girls
Age (yr)	10.8 ± 2.9, 5.7–16.5	11.4 ± 3.4, 5.8–18.4
	3.0 ± 0.3, 1.7–4.0	3.0 ± 0.3, 1.8–4.1
FSIQ	104.4 ± 12.9, 77–134	102.0 ± 11.3, 71–128
	0.4 ± 8.6, −18 to 23	1.9 ± 9.5, −44 to 26
Verbal Comprehension	104.9 ± 13.9, 64–145	103.1 ± 14.0, 65–136
	0.4 ± 8.6, −36 to 27	2.0 ± 11.2, −36 to 29
Working Memory	102.5 ± 13.1, 71–138	98.6 ± 12.4, 69–124
	−0.7 ± 9.3, −18 to 23	−1.4 ± 11.5, −61 to 18
Perceptual Organization	102.9 ± 15.3, 69–146	100.0 ± 11.9, 68–134
	0.0 ± 10.5, −29 to 23	0.2 ± 11.5, −48 to 31
Processing Speed	100.4 ± 11.8, 66–134	104.4 ± 13.2, 69–136
	5.7 ± 10.6, −28 to 34	5.4 ± 12.6, −30 to 39
Family annual incomea	4.09 ± 1.51, 1–7	3.88 ± 1.48, 1–7
Average number of years of parents' highest educational qualification	14.3 ± 1.74, 9–18.5	14.1 ± 1.55, 10.5–18.5
Average hours of spending time with parents for weekdays and holidays (hours)	2.24 ± 1.01, 0–3.5	2.34 ± 1.02, 0.08–3.5

^aData are mean ± SD, range. Family annual income was classified as follows: 1, annual income <2 million yen; 2, 2–4 million yen; 3, 4–6 million yen; 4, 6–8 million yen; 5, 8–10 million yen; 6, 10–12 million yen; 7, >12 million yen.