Table 1.

Descriptive Statistics and Correlations for Key Independent and Dependent Variables

	Mean (SD)	Correlation (N)
		Applied Problems
		54 mos	First grade	Third grade	Fifth grade	Age 15
Applied Problems
54 months	102.94	1
	(15.63)	(1053)
First grade	110.80	0.642	1
	(17.14)	(984)	(1023)
Third grade	115.05	0.584	0.703	1
	(15.00)	(934)	(933)	(1013)
Fifth grade	109.31	0.561	0.707	0.758	1
	(13.54)	(908)	(907)	(931)	(993)
Age 15	102.92	0.504	0.641	0.650	0.729	1
	(14.22)	(828)	(827)	(838)	(851)	(887)
Letter-Word Identification
54 months	98.93	0.584	0.527	0.468	0.449	0.450
	(13.52)	(1053)	(987)	(937)	(911)	(831)
First grade	111.99	0.452	0.570	0.556	0.503	0.439
	(15.79)	(986)	(1023)	(935)	(909)	(829)
Incomplete Words
54 months	96.67	0.463	0.389	0.373	0.332	0.268
	(13.63)	(1049)	(981)	(931)	(905)	(825)
First grade	95.92	0.348	0.357	0.368	0.326	0.296
	(11.18)	(979)	(1016)	(928)	(902)	(822)
Memory for Sentences
54 months	91.74	0.479	0.449	0.399	0.390	0.341
	(18.49)	(1050)	(984)	(934)	(909)	(828)
First grade	98.51	0.498	0.519	0.481	0.485	0.461
	(14.94)	(979)	(1016)	(928)	(903)	(822)
Picture Vocabulary
54 months	100.24	0.534	0.441	0.437	0.423	0.414
	(15.03)	(1053)	(990)	(940)	(914)	(834)
First grade	105.46	0.485	0.466	0.465	0.486	0.460
	(15.57)	(980)	(1017)	(930)	(904)	(824)
Attention (CPT % Correct)
54 months	0.72	0.343	0.313	0.262	0.252	0.231
	(0.22)	(1020)	(961)	(915)	(890)	(815)
First grade	0.95	0.214	0.208	0.255	0.195	0.175
	(0.08)	(965)	(993)	(912)	(886)	(812)
Impulsivity (CPT % Incorrect)
54 months	0.08	−0.302	−0.253	−0.214	−0.193	−0.177
	(0.11)	(1020)	(961)	(915)	(890)	(815)
First grade	0.02	−0.213	−0.187	−0.220	−0.214	−0.200
	(0.04)	(965)	(993)	(912)	(886)	(812)

Note: All correlations presented are statistically significant (p < .05)