. Author manuscript; available in PMC: 2010 Apr 30.

Published in final edited form as: Psychol Sci. 2009 Nov 23;21(1):75–79. doi: 10.1177/0956797609354073

Table 1.

Descriptive Statistics and Correlations

		Correlation
Measure	M	1	2	3	4
1. Digit Span (memory)	18.51 (3.94)	—
2. Vocabulary (verbal)	45.74 (9.51)	.43^**	—
3. Block Design (spatial)	42.47 (10.67)	.31^**	.45^**	—
4. Maternal differential negativity	−.09 (.55)	−.08	−.09	−.02	—
5. Sibling difference in behavior	−.06 (.57)	−.02	−.06	−.07	.44^**

Note: Digit Span, Vocabulary, and Block Design are subtests of the Wechsler Adult Intelligence Scale—Third Edition (Wechsler, 1997). Standard deviations are given in parentheses.

^**

p < .001.