. Author manuscript; available in PMC: 2014 Sep 1.

Published in final edited form as: Psychol Sci. 2013 Jul 1;24(9):1704–1713. doi: 10.1177/0956797613478618

Table 3. Results of the Random-Effects Regression Models of Amplification of Genetic (A), Shared Environment (C), and Nonshared Environment (E) Factors.

Variable	Intercept	Participant age	Time between assessments	Time 1 estimate	τ
Amplification of A
Primary model	−0.217 (0.026)^***	0.089 (0.048)^†	−0.006 (0.027)	−1.640 (0.839)^†	0.019 (0.074)
Alternate Model 1	−0.137 (0.021)^***	0.053 (0.008)^***	0.007 (0.009)	−1.041 (0.149)^***	0.000 (0.000)^†
Alternate Model 2	−0.124 (0.029)^***	0.055 (0.008)^***	0.001 (0.008)	−1.193 (0.149)^***	0.000 (0.000)^***
Amplification of C
Primary model	−0.354 (0.013)^***	0.018 (0.010)^†	−0.014 (0.007)^*	−0.801 (0.149)^***	−0.011 (0.027)
Alternate Model 1	−0.323 (0.016)^***	0.013 (0.005)^**	−0.009 (0.005)^†	−0.878 (0.071)^***	0.000 (0.000)
Alternate Model 2	−0.296 (0.023)^***	0.005 (0.010)	−0.034 (0.014)^*	−1.179 (0.211)^***	0.001 (0.000)^***
Amplification of E
Primary model	−0.216 (0.004)^***	0.000 (0.001)	−0.001 (0.001)	−0.907 (0.040)^***	0.000 (0.000)^*
Alternate Model 1	−0.216 (0.003)^***	0.000 (0.001)	−0.001 (0.001)	−0.965 (0.022)^***	0.000 (0.000)^***
Alternate Model 2	−0.216 (0.003)^***	0.001 (0.001)	0.000 (0.001)	−0.972 (0.021)^***	0.000 (0.000)^***

Note: Amplification refers to the carryover of early influences across time. Unstandardized coefficients are shown. Values in parentheses are standard errors. τ is a random effect that represents the estimated between-studies standard deviation in the true effect size (i.e., correcting for sampling variance). The primary model includes all data and weights. Alternate Model 1 does not include the Twins Early Development Study (TEDS) data. Alternate Model 2 does not weight estimates by their precision.

^†

p < .10.

p < .05.

^**

p < .01.

^***

p < .001.