Table 1.

Descriptive Statistics and Intercorrelations for Predictor and Outcome Variables

	M (SD)	Range	1	2	3	4	5	6	7	8	9	10	11	12
1. Income	55,600 (40,609)	55,000–380,000	--
Delay Aversion
2. Present a	232.28 (102.94)	5–300	.18*	--
3. M&M'S® a	4.97 (1.60)	1–6	.19*	−.05	--
Inhibition
4. NEPSY Statue b	10.42 (2.56)	4–14	.14†	.23*	.14	--
5. K-CPT Commission Errors b	55.45 (8.60)	30.0–72.5	−.02	−.15	.06	−.01	--
6. NEPSY Sentence Repetition b	10.33 (2.58)	4–16	.28***	.18*	.26*	.29**	−.13	--
7. K-ABC Hand Movement a	9.84 (2.85)	4–18	.07	.10	.15†	.24*	−.25*	.26**	--
8. McCarthy Numerical Memory a	4.65 (1.76)	0–10	.21*	.25**	.36**	.30**	−.13	.63***	.24**	--
Attention
9. K-CPT Omission Errorsb	53.32 (12.19)	36.9–95.3	−.17†	−.25**	−.16	−.39*	−.18†	−.35***	−.27*	−.23*	--
10. NEPSY Visual Attention b	10.45 (1.95)	4–15	.01	−.04	−.11	.03	.09	.09	.19†	.00	−.06	--
Inhibition/Attention
11. K-CPT ADHD Confidence Index b	52.38 (17.64)	1.8–98.7	−.12	−.36	−.04	−.42**	.01	−.33***	−.42**	−.21†	.77***	−.17†	--
Symptom Counts
12. DISC Att Symptoms c	2.90 (2.87)	0–9	−.16*	−.19*	−.02	−.33***	−.06	−.22**	−.16†	−.15†	.26**	−.13	.32***	--
13. DISC HI Symptoms c	3.79 (2.62)	0–9	−.23**	−.19*	−.14	−.24**	−.01	−.19*	−.14	−.12	.27**	−.03	.23***	.60

Note. NEPSY = A Developmental NEuroPSYchological Assessment, K-CPT = Kiddie Continuous Performance Test, K-ABC= Kaufman-Assessment Battery for Children, DISC = Diagnostic Interview Schedule for Children, Att = Inattention, HI = Hyperactivity/Impulsivity,

^ameasure was administered when children were 3 years old,

^bmeasure was administered when children were 4 years old,

^cmeasure administered when children were 6 years old.

^†p < .10,

^*p < .05,

^**p < .01,

^***p < .001