. Author manuscript; available in PMC: 2010 Jul 14.

Published in final edited form as: Behav Genet. 2006 Sep 15;37(2):273–283. doi: 10.1007/s10519-006-9113-4

Table 5.

Estimated parameters of income and education interaction models

	a	c	e	iorp	a′	c′	−2LL	Δ − 2LL_df	p values
Income
1. Full	2.39 (2.14, 2.65)	2.28 (2.02, 2.55)	0.93 (0.77, 1.09)	0.58 (0.46, 0.70)	0.13 (0.02, 0.25)	0.02 (− 0.12, 0.16)	42666.90	–	–
2. Drop a′	2.43 (2.07, 2.80)	2.14 (1.68, 2.60)	0.96 (0.82, 1.10)	0.58 (0.41, 0.75)	[0]	0.13 (− 0.02, 0.28)	42672.06	5.16₁	0.023
3. Drop c′	2.36 (1.99, 2.73)	2.22 (1.80, 2.65)	0.96 (0.82, 1.10)	0.58 (0.41, 0.75)	0.13 (0.01, 0.26)	[0]	42670.73	3.83₁	0.050
4. Drop a′, c′	2.42 (2.06, 2.79)	2.19 (1.76, 2.63)	0.96 (0.83,1.11)	0.56 (0.40, 0.73)	[0]	[0]	42674.49	7.59₂	0.022
Parental education
5. Full	2.37 (2.11, 2.62)	2.25 (1.99, 2.51)	0.93 (0.78, 1.08)	0.86 (0.69, 1.04)	0.12 (− 0.10, 0.33)	0.004 (− 0.24, 0.25)	44682.61	–	–
6. Drop a′	2.38 (2.03, 2.74)	2.15 (1.72, 2.58)	0.95 (0.81, 1.08)	0.87 (0.65, 1.08)	[0]	0.12 (− 0.09, − 0.34)	44686.30	3.69₁	0.055
7. Drop c′	2.37 (2.00, 2.73)	2.16 (1.74, 2.59)	0.97 (0.90, 1.04)	0.87 (0.66, 1.07)	0.11 (− 0.06, 0.28)	[0]	44685.68	3.09₁	0.079
8. Drop a′, c′	2.38 (2.02, 2.73)	2.16 (1.74, 2.58)	0.96 (0.82, 1.09)	0.88 (0.68, 1.08)	[0]	[0]	44687.66	5.05₂	0.064

Note: Lower and upper bounds of 95% confidence intervals are in parentheses