Data from: Heritability and correlations among learning and inhibitory control traits

To understand the evolution of cognitive abilities, we need to understand
both how selection acts upon them and their genetic (co)variance
structure. Recent work suggests that there are fitness consequences for
free-living individuals with particular cognitive abilities. However, our
current understanding of the heritability of these abilities is restricted
to domesticated species subjected to artificial selection. We investigated
genetic variance for, and genetic correlations among four cognitive
abilities: inhibitory control, visual and spatial discrimination, and
spatial ability, measured on >450 pheasants, Phasianus colchicus,
over 4 generations. Pheasants were reared in captivity but bred from
adults that lived in the wild and hence, were subject to selection on
survival. Pheasant chicks are precocial and were reared without parents,
enabling us to standardise environmental and parental care effects. We
constructed a pedigree based on 15 microsatellite loci and implemented
animal models to estimate heritability. We found moderate heritabilities
for discrimination learning and inhibitory control (h2=0.17-0.23) but
heritability for spatial ability was low (h2=0.09). Genetic correlations
among-traits were largely positive but characterised by high uncertainty
and were not statistically significant. Principle component analysis of
the genetic correlation matrix estimate revealed a leading component that
explained 69% of the variation, broadly in line with expectations under a
general intelligence model of cognition. However, this pattern was not
apparent in the phenotypic correlation structure which was more consistent
with a modular view of animal cognition. Our findings highlight that the
expression of cognitive traits is influenced by environmental factors
which masks the underlying genetic structure.