. Author manuscript; available in PMC: 2014 Feb 28.

Published in final edited form as: Compr Physiol. 2011 Jul;1(3):1603–1648. doi: 10.1002/cphy.c100059

Table 1.

Expected covariances for different types of relative pairs

Types of relatives	Coefficient for
Types of relatives	Additive genetic	Dominance	Shared environment
Spouse-spouse	0	0	1
Parent-child (living together)	1/2	0	1
Full sibs (living together)	1/2	1/4	1
Full sibs (living apart)	1/2	1/4	0
Half sibs (living together)	1/4	0	1
Half sibs (living apart)	1/4	0	0
Aunt/uncle-niece/nephew	1/4	0	0
First cousins (living apart)	1/8	0	0
Dbl. first cousins (living apart)	1/4	1/16	0
DZ twins (living together)	1/2	1/4	1
MZ twins (living together)	1	1	1