Table 1.

Notation key

Symbol	Meaning
i – j	Focal individual - Group mates of the focal individual
AD	Direct genetic effect \ Direct breeding value
AI	Indirect genetic effect \ Indirect breeding value
AT	Total genetic effect \ Total breeding value
ED	Direct environmental effect
EI	Indirect environmental effect
$${\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{D}}}^2$$	Direct genetic variance
$${\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{DI}}}$$	Direct–indirect genetic covariance
$${\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{I}}}^2$$	Indirect genetic variance
$${\mathrm{\sigma }}_{{\mathit{A}}_{\mathrm{T}}}^2$$	Total genetic variance
$${\mathrm{\sigma }}_{\mathit{Cage}}^2$$	Cage variance
$${\mathrm{\sigma }}_{\mathit{E}}^2$$	Error variance
$${\mathrm{\sigma }}_{\mathit{P}}^2$$	Phenotypic variance
$${\mathrm{\sigma }}_{{\mathit{E}}^{\mathit{*}}}^2$$	Pooled error variance
$${\mathrm{\sigma }}_{{\mathit{P}}^{\mathit{*}}}^2$$	Pooled phenotypic variance
h2	Direct genetic variance relative to phenotypic variance \ Heritability
T2	Total genetic variance relative to phenotypic variance
$${\mathrm{\sigma }}_{\mathit{z}}^2$$	Full variance
$${\mathrm{\sigma }}_{\mathit{b}}^2$$	Between-family variance
$${\mathrm{\sigma }}_{\mathit{w}}^2$$	Within-family variance
r	Relatedness within a family
N	Number of families
m	Number of records per family
o	Family size
n	Group size
^	Hat, denotes estimated values