. Author manuscript; available in PMC: 2012 Jan 24.

Published in final edited form as: J Polit. 2010;72(4):1189–1198. doi: 10.1017/S0022381610000617

Table A4.

Quantitative Disequilibrium Transmission Test of an Association Between DRD4 and Political Ideology, Including an Interaction with Dichotomous Friendship

	Estimate (standard error)	p-value
Intercept	2.82 (0.24)	0.00
Between-family component of DRD4-7R (b)	-0.05 (0.04)	0.12
Within-family component of DRD4-7R (w)	-0.19 (0.13)	0.14
Any Friends? (1 = Yes, 0 = No)	-0.01 (0.04)	0.74
Age	0.00 (0.01)	0.65
Male	-0.05 (0.04)	0.16
wAny Friends*	0.37 (0.16)	0.02
Deviance	1116.54
N	1941

Note: This table can be read like an ordinary regression except that the variable coding for DRD4 is divided into two variables to control for population stratification. The between-family component represents the average number of DRD4-7R alleles among all observed members of the subject’s family, while the within-family component indicates the excess number of DRD4-7R alleles relative to the family average. The results show that the interaction effect is robust to different specifications of the friendship variable. Null deviance = 1123.28.