In a landmark 2022 study, Kathleen Morrill and colleagues published in Science examined the genetic and behavioral diversity of over 18,000 dogs. The team surveyed owners and sequenced the DNA of more than 2,000 dogs to evaluate how well breed predicts behavior.
Findings revealed that while many behavioral traits are heritable, breed ancestry accounted for only about 9% of behavioral variation at the individual level. For traits like biddability—responsiveness to human direction—breed had some predictive power, but behaviors such as sociability or aggression were much less tied to breed ancestry.
Genomic analyses identified 11 loci significantly linked to behavior and more than 100 suggestive regions, underscoring the polygenic and complex nature of behavior. Unlike physical traits, which align closely with breed due to selective breeding, behavioral traits were broadly distributed across both purebred and mixed-breed dogs.
The study concludes that modern breeds are defined more by aesthetic traits than behavior, and that the behaviors associated with them often predate formal breed formation. This challenges the widespread reliance on breed stereotypes in pet selection, training, and policy.
Source: Morrill, K., Hekman, J., Li, X., McClure, J., Logan, B., Goodman, L., Gao, M., Dong, Y., Alonso, M., Carmichael, E., Snyder‐Mackler, N., Alonso, J., Noh, H. J., Johnson, J., Koltookian, M., Lieu, C., Megquier, K., Swofford, R., Turner-Maier, J., … Karlsson, E. (2022). Ancestry-inclusive dog genomics challenges popular breed stereotypes. Science, 376, 1019–1023.
