Genetic testing predicts appearance but not behavior in dogs

Genetic tests for behavioral and personality traits in dogs are now being
marketed to pet owners, but their predictive accuracy has not been
validated. To evaluate the reliability of such tests, we analyzed data
from Darwin’s Ark, a community science initiative that includes over 3,000
dogs with both genetic data and individual-level behavioral phenotypes.
None of the candidate variants had significant associations or predictive
power for behavioral traits as previously reported. However, we found
strong associations with aesthetic traits that differentiate breeds, such
as height, leg length, and ear shape. Our results suggest that earlier
studies using breed-average phenotypes, rather than individually measured
phenotypes, were confounded by population structure. Behavior in dogs is
polygenic and complex, and thus cannot be accurately predicted using tests
that consider only a few genetic variants. Furthermore, behavior in dogs
is only moderately heritable, and environmental influences inherently
limit the potential accuracy of genomic predictions. Developing
meaningful, accurate genetic predictions for complex traits that can
improve dog health and welfare will require very large cohorts of
individually phenotyped dogs.